The invention discloses a dry ice cleaning system and method applied to the electronic module assembly process. The cleaning system comprises an ice breaking mechanism, an injection pipeline, a mechanical arm, a cleaning base and a nozzle. Multiple electronic modules are arranged in a parallelogram array manner and fastened to the cleaning base, and a heating structure for heating the electronic modules is arranged on the cleaning base. The ice breaking mechanism provides dry ice particles for the nozzle through the injection pipeline. The nozzle is arranged on the mechanical arm, and the nozzle is located above the cleaning base and can be aligned at the electronic modules for cleaning. The nozzle and the mechanical arm are rotationally connected so as to adjust the included angles between the nozzle and the surfaces of the electronic modules. The mechanical arm drives the nozzle to clean the surfaces and the sides of the electronic modules according to a snakelike reciprocating path.The advancing direction of the snakelike reciprocating path is parallel to the line direction of the parallelogram array. The snakelike reciprocating cleaning path is short in route, the speed is high, the dry ice cleaning system and method adapt to cleaning of the electronic modules in the parallelogram array form, and the automation degree is high.