The road tester of the MST - S motorcycle is a special apparatus on the road trial. With the application of photo electricity transmission sense principle, the instrument, whose kernel is based on the AT89S52 CPU, can inspect the running time on line within the distance through the photoelectricity viewfinder that is installed on the experimental road. Then it calculates the multiparameter in the motorcycle driving and saves the data into the DS1642 chip, which could resist the volatility and administer the time. The experimentation has the ability to complete the testing items for oil consumption veraciously via the mounted fuel flowmeter. Connecting the keyboard query with the intermittence in the survey, the meterage can intercept various intervals. At the same time, for adopting the anti-jamming, which increase the experimental reliability and survey precision respectively, it reduces the trial error.