Traditional direct power purchase transactions are mostly based on the matching of bilateral quantity and prices of electricity. It lacks effective means to optimize the quality of electric transmission of direct power purchase. Starting from the electricity characteristic curves of the purchase and supplier sides， an auxiliary model based on bilateral patterns technology matching is proposed for transaction. Direct power purchase scheme which is beneficial to grid operation， participants' behavior and reduction of uncertainty fluctuations is discussed in the direct power purchase market environment. The data collected from a power company is used as an example for matching analysis and the results demonstrate the validity of the model.