In order to meet the needs of the rotor field dynamic balance, improved test precision, a field dynamic balance test system was developed based on virtual instrument technology, the correlation method was used to accurately extract the vibration signal amplitude and phase, dynamic balance experiments were conducted with influence coefficient method. Rotor dynamic balance tests were made many times on the lathe spindle. The experimental results show that the unbalance vibration of the rotor has been effectively suppressed after adding appropriate test heavy, the vibration amplitude is reduced significantly, the required balance precision to the rotating machinery is achieved.It has important significance to reduce machine noise and bearing wear, and to improve the performance and life of the machine. Also it helps to improve the working efficiency of the machine and to ensure the safety of machining operator.