In the traditional photovoltaic storage virtual synchronous generator (VSG) system, the battery handles the fluctuation of photovoltaic power by frequent charging and discharging. This leads to premature battery failure. To optimize battery operation, a VSG control strategy for a photovoltaic system with storage considering maximum power output and energy storage coordination is proposed. First, the proportional correlation between output frequency and DC side voltage deviation is established to realize maximum output of PV power and the inertia support of the VSG. Secondly, the sagging characteristic is used to control the battery power output to enhance the flexibility of battery energy management and this can realize the primary frequency regulation function of the system. Thirdly, a segmented control scheme to stabilize the DC side voltage is designed to ensure that the DC side voltage of the system is within a reasonable range when the system is working normally. Finally, simulation experiments verify that the proposed method not only retains the inertia support and primary frequency regulation functions of VSG control, but also realizes the maximization of PV power output and reduces the dependence on batteries.