The nonlinear dynamic lubrication analysis mathematical model of spherical hybrid gas bearings was established with the hemisphere spiral groove hybrid gas bearings as the researching object,and perturbation control equation was derived by means of the partial derivative method.The finite difference method was employed to discrete the perturbation control equation in generalized coordinate system,and the difference expression of perturbation pressure was derived.The relational expression involving the relationship between the bearing dynamic characteristic coefficients and perturbation pressure was deduced.The transient perturbation pressure distribution of threedimensional micro gas film,nonlinear gas film force,dynamic stiffness and dynamic damping coefficients of bearings were numerically computed using VC++60 programs.The influence law of supply pressure,speed and eccentricity ratio on the bearing dynamic stiffness and damping coefficients was researched.The results show that the influence of bearing’s speed,eccentricity and supply pressure on the dynamic characteristics of gas film is significant.