A method for decoding Polar codes includes: receiving a Polar code having a length of N, and dividing the Polar code into m subcodes that are coupled to each other, each subcode has a length of N/m, and each of N and m is an integer powers of 2; calculating squared Euclidean distances of input bits in the m subcodes, to obtain minimum squared Euclidean distances of the input bits that are independent of each other; obtaining, accordingly a minimum squared Euclidean distance of input bits that are coupled to each other in the m subcodes; and obtaining input bits that are in the m subcodes and that meet the independent minimum squared Euclidean distances and the combined minimum squared Euclidean distance, and obtaining a decoding result of the Polar code with reference to relationships between the m subcodes and the Polar code.