To address the issue of power-frequency fluctuations in a wind-solar-hydrogen storage grid-connected system under varying operating conditions when using traditional virtual synchronous generator (VSG) control strategies, an adaptive VSG parameter control strategy is proposed. A grid-connected model of the wind-solar-hydrogen storage system is constructed. The system is equipped with inertia and primary frequency modulation (FM) characteristics through VSG technology, and an active small-signal model of the VSG is established to analyze the impact of parameter variations on the system. The dynamic characteristics of inertia damping are analyzed using oscillation curves of angular frequency deviation and its rate of change during system disturbances. A high-precision fuzzy algorithm is designed to achieve nonlinear parameter adjustment, and the range of parameter values is determined. A simulation model is built on the Matlab/Simulink platform for verification. The results show that under conditions of active power reference command variations and local load mutations, the power-frequency response of the system is improved after applying the fuzzy adaptive control of VSG parameters. The fluctuations in DC bus voltage and electrolyzer are reduced, the recovery speed is accelerated, and the system stability is enhanced.