Ambivalence brings great uncertainty to workers’ decision making of intentional unsafe behaviors. It is of great theoretical and practical significance to find the factors that have significant regulating effect on workers’ ambivalence. [Research Content] On the basis of constructing the decision-making model of workers’ intentional unsafe behaviors under the ambivalence of workers, this paper analyzed the moderating effect of optimism bias on the ambivalence of workers, and employed the structural equation model to empirically verify the proposed hypothesis. [Empirical results] Individual optimism bias has a significant moderating effect on the ambivalence in the decision-making process of workers’ behavior. Workers with higher optimism bias are more likely to have intentional unsafe behaviors. At the same time, the generation of optimism bias is related to workers’ self-esteem and risk preference. [Enlightenment] Managers should pay more attention to workers’ optimism bias psychology, and in particular, psychological counseling should be conducted regularly for workers engaged in high-risk work for a long time to help workers establish a correct view of risk.