Aiming at the problem of grid-connected voltage regulation difficulties and reduced system stability of photovoltaic grid-connected inverters in high penetration environments, this paper proposes a voltage regulation strategy based on flexible control. First, this paper analyzes the challenges that photovoltaic inverters bring to voltage and frequency stability during grid connection. Then, a grid-connected voltage regulation method for inverters based on flexible control is proposed, which improves the dynamic response performance of the inverter by introducing adaptive control algorithms and multi-objective optimization strategies. This paper specifically designs a dual-loop feedback control structure, in which the outer loop is used to adjust the grid-connected voltage and the inner loop is used for current tracking. Experimental results show that under the condition of ± 10% voltage disturbance, the root mean square error (RMSE) of the system is 0.00283 pu, and it recovers to the ± 2% range of the reference voltage in about 5.467 s. Under harmonic interference, the total harmonic distortion (THD) is reduced to 0.00%. These results significantly improved the voltage regulation accuracy, dynamic response speed and harmonic suppression capability of photovoltaic inverters in complex power grid environments, verified the effectiveness and advantages of flexible control strategies, and effectively solved the problems of photovoltaic grid-connected voltage regulation and system stability.