With the increasing of photovoltaic capacity in urban power grid, the research on capacity planning is also imminent. In this paper, considering the time sequence relationship between photovoltaic output and urban load, combined with the frequency regulation limitation of thermal power units, a photovoltaic capacity planning model based on time series production simulation is established by using mixed integer linear programming method. The planning goal is to meet the load demand, and the comprehensive power generation cost is the lowest, including the cost of frequency regulation and light abandonment of thermal power units. Finally, taking the measured data of a certain region in China as an example, the effectiveness of this method is verified, and the relationship between photovoltaic access capacity and load type is analyzed, which provides a reference for photovoltaic capacity planning of urban power grid.