This paper establishes a risk model in constructing municipal civil engineering buildings based on finite element differential equations. At the same time, we set up a dynamic differential equation for the hidden danger of accidents in municipal engineering construction. This paper combines the differential game model of government intervention coordination and enterprise construction dynamics. In this way, we obtain the feedback Nash equilibrium solution under government intervention. The research results show that government subsidies can promote cooperation between the two sides of the construction industry chain. This paper points out that the optimal control strategy should consider the strategy choice of the regulatory authorities.