This paper presents a comprehensive survey on the co-optimization of semantic communication and control. In cyber-physical systems, traditional separation of communication and control is inadequate due to resource constraints and complex environments. Semantic communication, focusing on task-relevant information, offers a new paradigm. We review semantic communication foundations, wireless network control systems, and joint semantic communication-control system models. Key technologies, including joint encoder-controller optimization, semantic-aware scheduling policies, and intelligent-algorithm-based joint optimization, are discussed. Challenges such as generalization of semantic representations, error tolerance in control-centric systems, lack of theoretical foundations, and integration with large models and multi-modal systems are identified. Despite these challenges, semantic communication and control co-optimization holds great potential for enabling efficient, intelligent, and reliable cyber-physical systems, and we believe continued research will drive significant advancements in this field. The paper provides valuable insights for researchers aiming to develop more sophisticated communication and control strategies in resource-constrained scenarios.