The present disclosure discloses an electron linear accelerator system. In the present disclosure, a fast-switching dual-path microwave system is proposed, wherein, one path can be directly connected to an accelerating tube, and the other path can be input into the accelerating tube after a magnitude of the microwave power is changed by devices such as an attenuator, a power divider, a pulse compressor or even an amplifier etc., so as to achieve fast switch of the power input into the accelerator and adjust the energy output by the accelerator.