The engine mount transmission force can be used as an important basis to evaluate the vibration isolation performance of the engine mounting system. However, there is a lack of testing equipment and methods for the transmission force. The force sensor and the test method of the transmission force is studied. The finite element model of the mounting element is established to analyze the arrangement position of the sensor. The force sensor is developed based on the resistance strain gauge. The sensor is arranged in the middle of the intermediate bolt. The test system of mount transmission force is established at the same time. The driving force of driving wheel is obtained through the chassis dynamometer test. The force sensor is calibrated base on the test data. The results of mounting transmission force are obtained through the vehicle road test.