Aiming at the problems of poor response speed, insufficient anti-disturbance performance and poor observation accuracy of traditional sliding mode observer in maximum power tracking of offshore wind turbines, a control strategy of improved dual-loop anti-disturbance control and adaptive full-order sliding mode observer is proposed. The fal function is replaced by a smooth continuous function to weaken the jitter; the adaptive rate is designed to obtain a smoother back electromotive force, and a phase-locked loop algorithm is introduced to estimate the rotor speed and position angle. Comparative experiments show that the strategy proposed in this paper improves the speed tracking response speed by about 24.3%, the maximum speed error is reduced from 0.70 to 0.34 rpm, and the maximum rotor position error is reduced from 0.045 to 0.012 rad. The observation accuracy is also significantly improved in steady state. Under this strategy, the system anti-disturbance performance is enhanced, the response speed is improved, and the observation accuracy is significantly improved, which improves the maximum power tracking effect.