Taking the most common two-machine interconnected system in ship power network system as the research object, the perturbation solution of the system under periodic electromagnetic disturbance has thus been obtained based on the theoretical analytical method. According to Melnikov chaos criterion, the perturbation solution is a chaotic solution, which verifies the existence of chaotic behavior in the system. The theoretical analysis results show that the chaotic behavior of the system can be controlled by adjusting the system parameters or initial conditions, with the corresponding numerical simulation results confirming the conclusion of theoretical analysis.