High penetration renewable energy grid connection has exacerbated the volatility and uncertainty of distribution network operation. To improve the flexibility and anti-interference ability of distribution networks, a flexible supply-demand collaborative planning method for networks containing high penetration of renewable energy is proposed. From the supply-demand relationship of system operation flexibility, flexibility evaluation indicators are defined. A collaborative planning strategy for distribution network flexibility supply and demand is proposed, and a bilevel optimal allocation model for the network flexibility resources considering seasonal characteristics is established. The upper layer formulates a flexible resource allocation scheme with the objective of minimizing investment cost and insufficient flexibility rate. The lower layer takes into account the response of the demand side to seasonal electricity price incentives for active and reactive power joint optimization to achieve the optimal scheduling of multi scenario time series operation of the network during the day. To solve the bilevel mixed integer nonlinear programming model, a second-order cone relaxation is used to convexly optimize the power flow equation, and then the bilevel model is transformed into a single-layer mixed integer second-order cone programming model using the KKT condition. Simulation results show that this method effectively improves the flexibility and stability of distribution network operation, and provides decision-making reference for large-scale grid connection of distributed renewable energy and other related projects.