To enhance the grid connection stability of virtual synchronous machines, a global optimization design method for virtual synchronous machine control parameters was proposed. Firstly, a small-signal model of the virtual synchronous generator with virtual exciter and governor was established, and the system eigenvalues were obtained by solving the state matrix. Secondly, the sensitivity of the controller parameters to the position of eigenvalues was studied, and a wide range of parameter optimization was conducted using genetic algorithms based on the main eigenvalue positions. Finally, analytical solutions of the model and MATLAB/Simulink simulation data were compared. The results show that significant improvements in frequency stability can be achieved by optimizing a wide range of virtual synchronous machine parameters. After optimization, the system response transient stability time is 0.25 s, only 5% of the transient stability time with general parameters, and the frequency stability improves noticeably with load changes.