In order to solve the challenge of key object identification in digital engineering quality control, in view of the shortcomings of the existing dynamic programming algorithms, this study proposes an innovative key object identification method for quality control based on the all-index intelligent method. This new scheme uses the principle of overlapping sub-problem theory to accurately identify and locate the key influencing factors, and accordingly carries out a wise classification of indicators to reduce possible interference. At the same time, by using the unique mechanism of the all-index intelligent method, the design strategy of engineering quality control is cleverly constructed. The empirical results show that the scheme shows a significant improvement compared with the traditional dynamic programming algorithm in terms of key performance indicators such as the accuracy of key object identification and the processing efficiency of key factors in quality control, showing its obvious strong advantages. In digital engineering, the identification of key objects of quality control plays a crucial role, which can accurately predict and optimize the growth trend and output results of key object identification of digital engineering quality control. However, in the face of complex simulation tasks, traditional dynamic programming algorithms show some inherent shortcomings, especially when dealing with multi-level challenges, their performance is often unsatisfactory. To overcome this problem, this study introduces a new idea of identifying key objects in quality control optimized by the all-index intelligent method, and accurately controls the influencing parameters through the overlapping sub-problem theory, which is used as the road map for index allocation, and then uses the all-index intelligent method to innovate and construct a system scheme. The test results clearly point out that in the context of the evaluation criteria, the new scheme has been significantly optimized in terms of accuracy and processing speed for a variety of challenges, showing stronger performance superiority. Therefore, in the key object identification link of digital engineering quality control, the simulation scheme based on the all-index intelligent method successfully overcomes the shortcomings of the traditional dynamic programming algorithm, and significantly improves the accuracy and operation efficiency of the simulation.