Motorcycle chassis dynamometer is used for motorcycle performance and emission test as well as creating working conditions for other professional equipment that need stable constant speed, constant force and constant power conditions to test motorcycles. In the system of motorcycle chassis dynamometer, the friction in the drum can be measured more accurately by the test of parasitic power (internal loss) coasting, which makes the measurement of the external force exerted by the motorcycle on the drum more accurate. The system also has the function of simulating the friction coefficient of different road, and measuring the output power and torque of motorcycle engine under different road conditions. The system can also force the motorcycle back to the set speed, measure the output power under the speed and the power torque curve formed by connecting each speed point. The equipment has the advantages of superior performance, complete functions,