The invention discloses a motor vehicle axle load testing device used as a braking station sensor, which mainly comprises a working platform stand, four working air cylinders, a force measurement sensor, a sensor fixing base and a drum type braking force testing platform, wherein the four working air cylinders are arranged in the working platform stand, the drum type braking force testing platform is fixedly installed at a center position in the working platform stand, the working air cylinders are respectively arranged at the positions of the four corners of the inner side of the working platform stand and are fixedly installed with the inner wall of the working platform stand, the force measurement sensor is fixedly installed on the sensor fixing base, and the working push rods of the working air cylinders are opposite to a force measurement contact of the force measurement sensor. The invention has the advantages that the invention has the function of measuring braking force and axle load and reduces the parking and positioning times and the test time; the measurement is accurate and reliable; and the entire height of the testing platform is lowered, and the maintenance is easy.