In view of the problem that the balance rate of pumping unit needs to be tested frequently in the oil field, the accuracy of conventional current method is insufficient, a portable balance rate tester of pumping unit based on ADE7755 and acceleration sensor is developed in this paper. Firstly, the basic principle and overall structure of the balance rate tester of pumping unit using electric energy method are introduced, and principle of the acceleration sensor and wireless communication technology are analyzes the working the acceleration sensor circuit and the flow chart of the system software. At last, the balance rate tester was used in Shengli oilfield. The field results show that the balance instrument is portable, easy to operate and accurate. It is recognized by the field staff and can provide accurate balance rate reference for the pumping unit.