The embodiments of the present invention provide a decoding method and a decoding device for a polar code cascaded with CRC. The decoding method includes: performing SC-List decoding on a Polar code according to the number of survival paths L to obtain L survival paths, where L is a positive integer; performing cyclic redundancy check on the L survival paths respectively; and increasing the number of survival paths when all the L survival paths fail to pass the cyclic redundancy check, and acquiring a decoding result of the Polar code according to the increased number of survival paths. In the embodiments of the present invention, the path number of survival paths is adjusted according to a result of the cyclic redundancy check, so as to output paths as much as possible, where the output paths can pass the cyclic redundancy check, thereby improving decoding performance.