In traditional power flow calculation used constant power load model, it was completely unreasonable to assume that all load nodes in power system can be classified as PQ nodes.In that the result of constant power load model does not accurately reflect the distribution characteristics of network power flow. To put forward power flow calculation considering load models ,such as constant power load ,constant current load and constant resistance load, derives error equations of the node power, calculates element of Jacobian matrix. So, by using MATLAB simulation software ,the program for power flow are presented, which based on the method of different load models, taking 21-node system for example and makes comparative calculations. The research shows that power flow calculation considering different load models can get more reasonable solution.