The invention relates to a hybrid power complementary coordination optimization scheduling method considering a power flexibility margin, and the method is characterized by comprising the following steps: establishing a mathematical model for calculating the power supply up-regulation flexibility margin and the down-regulation flexibility margin; constructing a hybrid power complementary coordination optimization scheduling model which takes the minimum sum of the fire coal cost and the pollution gas emission control cost in the system as a target and takes the power flexibility margin into consideration; and formulating a hierarchical scheduling strategy of preferentially and fully absorbing wind power, photovoltaic and follow-up water and electricity regulation to stabilize system net load fluctuation and finally bearing system residual net load by thermal power. The method employs the traditional particle swarm algorithm to calculate the overall optimal output power of water and electricity, employs a heuristic priority sequence method to determine a thermal power generating unit combination, calculates the optimal output power of the thermal power generating unit by improving the particle swarm algorithm, and makes a power generation plan of four heterogeneous energy power supplies of wind, light, water and fire in a dispatching period. The method can effectively improve the power flexibility margin and promote the consumption of renewable energy sources.