Under the current general trend of building energy conservation, the multi heat source combined central heating system has attracted widespread attention in the industry because of its advantages such as energy conservation, heating reliability and system flexibility. However, due to the increase of the number of heat sources, the complexity of the pipe network of the central heating system increases significantly. For most multi heat source central heating systems, it is usually difficult to obtain the best hydraulic condition to achieve the ideal heating effect. In this paper, an optimal regulation strategy is proposed. Its basic idea is to establish the mathematical model of multi heat source central heating system by using the method of graph theory, combined with the idea of synergy theory, take the minimum total pump work of the system as the optimization objective, take the mass balance, energy balance and system supply-demand balance as the limiting conditions, and introduce the heat source preference factor to establish the collaborative optimization equation, solve the optimal regulation method to meet the requirements of hydraulic condition, thermal condition and heat source scheduling of the system. The strategy is applied to a multi heat source central heating system. The results show that the optimal regulation strategy can ensure the matching degree of supply and demand of each heat exchange station within the expected range. At the same time, compared with the differential pressure control strategy, the total pump work of the system can be reduced by 21%.