Psychosocial safety climate (PSC), an important measure of the psychological safety of employees and organizational health, has become a significant factor affecting psychological capital and thus affecting the outcome of engineering projects. This study aims to analyze the mental health and safety of construction workers in different situations. Based on 124 valid questionnaires collected from participants in Qianhai, Shenzhen, and 502 valid questionnaires from Guangzhou, this paper analyzes the PSC of engineering construction projects using the four-factor scale (PSC-12) from four dimensions of management support and commitment, management priority, organizational communication, and participation. It is found that, compared with ordinary engineering construction projects, there are higher PSC levels in megaprojects: the individual level of subjective initiative, the pursuit of self-worth, organizational level of funding, and political orientation can also effectively improve the PSC level. These research results can deepen the understanding of the PSC of engineering construction projects, and provide a practical reference for its improvement.