Under the “double high” background, the new power system is faced with the stability problem of complex nonlinear mechanisms. The interaction between the nonlinear combination of the dead zone in the traditional unit governor and the wind power controller affects the frequency stability of the system to a certain extent. Therefore, on the basis of Nye’s theorem, the influence law of system frequency oscillation with different dead-zone nonlinear combinations is explored, mainly focusing on three aspects: dead-zone type, size and order, involving both single and multi-dead-zone systems. The stability of the nonlinear system is analyzed theoretically, and the critical amplitude and oscillation frequency of the system are determined from the stable limit cycle condition. By changing the type and order of the dead zone, the ability of the unit to support the system frequency is affected, and the relationship between system frequency stability and the critical amplitude is pointed out. The above theoretical analysis is simulated and verified in Matlab/Simulink. It is concluded that the size and type of the unit dead zone will change the critical amplitude and oscillation frequency of the system. This provides a certain reference for the unit to configure the dead zone.