This paper establishes an evolutionary game model to analyze the formation mechanism and influencing factors of herding effect in unsafe behavior by considering the psychological benefits, physiological benefits and risk costs of employees when they following unsafe behaviors, and the costs of violating group norms, the benefits of safe behavior when they are not following, and the power of supervision and the fluke mind that the law cannot be enforced when everyone is an offender. The research results show that the generation of herding effect in unsafe behavior is affected by a series of factors. Numerical analysis of the evolution of multiple equilibria shows that the benefits and costs of following unsafe behavior, supervision are significantly correlated with the generation of herding effect. Finally, based on the results of numerical analysis, this paper will give suggestions for the control of the herding effect in unsafe behavior and provide theoretical support for the phenomenon of group unsafe behavior in safe production.