The invention discloses a quality control system and a method for a radiotherapy device. The quality control system comprises a control terminal connected to a host computer for outputting a control command to the master machine; the host computer for controlling the operation of an orientator connected to the host computer based on the control command; the orientator for operating based on the control command, collecting the output quantity of the radiotherapy device and transmitting to a dose meter; and the dose meter for detecting the output quantity of the radiotherapy device collected bythe radiotherapy device. Accordingly, the invention further discloses a quality control method for the radiotherapy device. By adopting the orientator to collect the output quantity of the radiotherapy device, the artificial measuring error is reduced, the measurement time is shortened, the working efficiency is improved, and the operating staff is safe from the radiation hazard.