Abstract: In response to issues such as voltage exceeding limits, harmonic amplification, three-phase imbalance, and power factor reduction after high proportion distributed photovoltaic access to the distribution network, this paper takes the impact mechanism governance resources simulation verification as the main line to analyze the effects of photovoltaic output fluctuations, inverter control coupling, and source load timing mismatch on power quality. A collaborative governance scheme combining source side active support, grid side layered compensation, load side flexible response, and storage side smooth support is proposed. Based on the improved IEEE33 node 10kV feeder, a simulation model is constructed, and three scenarios are set up: no governance, single grid side governance, and source grid load storage collaborative governance. The governance effect is evaluated from indicators such as voltage deviation, harmonic distortion, three-phase imbalance, power factor, and network loss. The results show that collaborative governance can control the maximum terminal voltage per unit value at 1.034, reduce the total harmonic distortion rate of voltage to 2.1%, reduce the three-phase imbalance to 1.7%, improve the power factor to 0.98, and achieve a voltage qualification rate of 99.7%. This scheme can balance fast compensation and source load coordination, providing a reference for power quality management in high penetration distributed photovoltaic distribution networks.