The invention discloses a passive intermodulation interference cancellation method and system based on a recursive network. The system and the method comprises a passive intermodulation interference cancellation system (a cancellation system for short) based on the recursive network and a passive intermodulation interference cancellation method (a cancellation method for short) based on the recursive network. The cancellation system comprises a feature analysis processing module, a recursive network estimation module and a cancellation feedback adjustment module. The cancellation method comprises the steps of 1, receiving a signal; 2, judging whether the received signal is in a pilot time slot or not, and jumping to the 3 or 6; 3, extracting features and carrying out network initialization; 4, preprocessing the received signal and removing pilot; 5, carrying out prediction training on the recursive network, thereby obtaining a one-step-ahead prediction recursive network; 6, preprocessing a data transmission time slot receiving signal; 7, predicting a PIM interference signal of a next moment by employing a result of the 5, and finishing interference cancellation; 8, processing collected difference values before and after decoding, feeding back a processing result, and updating network parameters; and 9, judging whether cancellation is finished or not, and deciding to wait or to jump to the 6. According to the method and the device, the system adaptability is high, the cancellation precision is high, and the hardware realization is easy.