With fierce global market competition and rapid technological changes, developing new toy products has become increasingly complex. Coupled with declining birthrates and societal shifts, STEAM toys with educational value have become parents’ top choice. Maintaining existing customers, however, is more critical than acquiring new ones. Finding enduring elements that attract consumers can enhance customer loyalty, leading to sustained or broader adoption of products. This study focuses on STEAM toys. It first employed a semi-structured quantitative questionnaire to analyze Taiwanese parents’ opinions and purchasing priorities regarding STEAM toys, collecting 429 responses. From these, 40 representative families were selected for qualitative research, including “Picture Life Diary of Children and Toys” documenting parent-child play interactions over a week. Researchers also conducted home visits, using the “Miryoku Engineering Evaluation Grid Method” to identify STEAM toy types and features that encourage repurchase. Research and surveys have found that Taiwanese parents purchase STEAM toys for three primary reasons: (1) to develop their children’s diverse abilities in a well-rounded manner, (2) to encourage engineering thinking, and (3) to promote artistic creativity. Additionally, Taiwanese parents tend to favor toys that allow their children to create their own designs, are suitable for all ages, and have expandable functions. The top three favorite product categories are: (1) building blocks, (2) tracks, and (3) magnetic tiles. The top three toys that Taiwanese children love the most are LEGO, Qbi toys, and magnetic tiles. These types of STEAM toys offer diverse play methods, are easy to use, and have educational value. Furthermore, STEAM toys that parents are willing to repurchase must be highly creative, interactive, expandable, attractive to children, and suitable for both active and passive play. In terms of repurchase strategies, the three most appealing strategies for parents are: (1) word-of-mouth recommendations, (2) system compatibility, (3) product demonstration tutorials. Among these, parents trust kindergarten teachers’ recommendations the most. They believe that these STEAM toys are not just playthings but also contribute to their children's learning and development. Compatibility with existing toys, such as through expansion kits, additional accessories, or cross-brand mixing and matching. When purchasing high-priced STEAM toys, parents often go online to watch product demonstrations, read reviews, and view photos or videos of adults and children playing with the toys. They rely on unboxing introductions to assess whether the toy is enjoyable and consider whether it suits their children, imagining if the joyful scenes of others playing can be recreated in their own homes. Afterward, try to construct a STEM toy product development and design strategy map that can improve customer loyalty, and then further confirm the toy product development and design process from the enterprise side. The interviews revealed that most toy manufacturers in Taiwan have well-established and mature development and verification processes for toy product design. However, due to a lack of comprehensive understanding of STEAM education, few companies can propose specific design processes for STEAM toys. Therefore, this study conducted additional interviews with STEAM education experts and integrated the existing design processes of companies to derive a STEAM toy product development and design process suitable for enterprise use. Meanwhile, this study analyzed the attractiveness factors of STEAM toy designs that strongly appeal to parents and motivate them to spend money on such products. Seven key design factors were identified and compiled: (1) attractive toy categories, (2) the ability to provide emotional appeal, (3) educational value, (4) distinctive product appearance and functionality, (5) innovative and diverse play methods, (6) designs aligned with real-world practicality, and (7) age-specific design considerations. Additionally, the study proposed nine specific design approaches and 48 design guideline recommendations. Marketing strategies for STEAM toys remain traditional in Taiwan, relying on distribution channels and sales methods. However, as new-generation parents shift their purchasing habits, supplementary media are essential to convey the educational value of STEAM toys effectively. Therefore, this study provides six strategies for enterprises to attract new-generation parents and encourage repeat purchases: (1) clarifying product applicability, (2) enhancing product extensibility, (3) stimulating purchase desire, (4) creating opportunities for impulsive buying, (5) improving shopping convenience, and (6) strengthening brand loyalty. The primary goal of this research is to compile strategies for STEAM toy development and design that enhance customer loyalty. Its contributions include: (1) identifying the key factors that enhance customer loyalty in STEAM toys, (2) developing a STEAM toy development process model applicable to enterprises, (3) proposing design guidelines for STEAM toys, and (4) formulating marketing strategies tailored to new-generation parents. Taiwan, once renowned as the “Toy Kingdom,” has seen its toy industry decline into a “sunset industry,” with fewer locally developed brands. The findings of this study aim to assist the industry during concept development by enabling swift and accurate direction-setting. This research provides a fresh perspective for transforming Taiwan’s toy industry and supporting the growth of start-ups.