The invention relates to a master control test system and method for a large-sized wind generating set. The system comprises a master control system, a current change system, a slurry change system, a simulation fan and a wind field monitoring system which are connected with a router respectively, wherein the master control system, the slurry change system, the current change system and the wind field monitoring system are connected with one another to constitute a communication system network; and the simulation fan is in communication connection with the main control system. In the invention, a wind power unit model is established for simulating the wind field running environment, so that reappearance of the unit running condition is realized, and testing and debugging are not influenced by the properties such as randomness, intermittence and the like of wind; and a corresponding test scheme is made, and matters needing attention during testing are concluded. According to the test system, the problem of difficulty in comprehensively and dynamically testing a wind generating set control system is solved effectively, the high reliability and high dynamic performance of a master control system are ensured, defects are exposed in advance, the research and development period is shortened, field debugging time is reduced, and the research, development and delivery quality of a wind generating set master control system is enhanced.