Taking graphene as the sensitive material of the pressure sensor, Si as the base material, PN as the graphene protection material and Wheatstone bridge as the force-electric transformation measurement circuit, a new structure of silicon-based graphene pressure sensor was constructed. Based on the established theoretical model of the sensor with the foam experimental method, the relationship between the pressure of the sensor and the central change displacement was analyzed. And by combining with the ANSYS software static nonlinear analysis unit, the value analysis and finite element simulation were carried out to analyze the characteristics of deflection deformation of the graphene film. The results show that the theoretical analysis results of graphene film pressure and deflection deformation are consistent with the simulation ones.