The dynamometer system for the measurement of power and torque of power machinery equipment is mainly composed of dynamometer motor, dynamometer mechanism and control system. Such systems are widely used in performance testing of mechanical transmission components. The importance of the dynamometer system in the industrial field is briefly described. The classification of dynamometer systems is summarized, and the advantages and disadvantages of all kinds of dynamometers are analyzed. The structure, principle and application scenarios of the current dynamometer systems are introduced. Several classic control strategies of dynamometer systems are summarized. Finally, the application of dynamometer in the performance test of transmission, gearbox, engine and automobile chassis is introduced.