A polar code encoding method, comprising: obtaining, by a transmit end, a target information sequence, wherein a length of the target information sequence is K; determining, according to the length K, a cyclic redundancy check CRC length M for the target information sequence; adding an M-length CRC check code to the target information sequence, and performing polar encoding on the information sequence obtained after the check code is added, to obtain a polar code; and sending, to a receive end, the polar code; wherein the determining, according to the length K, a cyclic redundancy check CRC length M for the target information sequence comprises: determining, according to a pre-stored check code mapping relationship between the length K of the information sequence and the CRC check code length M, the CRC check code length M corresponding to the target information sequence, wherein in the check code mapping relationship, a CRC check code length M corresponding to an information sequence with a longer length K is greater than or equal to a CRC check code length M corresponding to an information sequence with a shorter length K; wherein the mapping relationship is as follows: when K≤128, M equals to 8; when 128<K≤512, M equals to 16; when 512<K≤8192, M equals to 24; when K>8192, M equals to 32, wherein K and M are in unit of bits. obtaining, by a transmit end, a target information sequence, wherein a length of the target information sequence is K; determining, according to the length K, a cyclic redundancy check CRC length M for the target information sequence; adding an M-length CRC check code to the target information sequence, and performing polar encoding on the information sequence obtained after the check code is added, to obtain a polar code; and sending, to a receive end, the polar code; wherein the determining, according to the length K, a cyclic redundancy check CRC length M for the target information sequence comprises: determining, according to a pre-stored check code mapping relationship between the length K of the information sequence and the CRC check code length M, the CRC check code length M corresponding to the target information sequence, wherein in the check code mapping relationship, a CRC check code length M corresponding to an information sequence with a longer length K is greater than or equal to a CRC check code length M corresponding to an information sequence with a shorter length K; wherein the mapping relationship is as follows: when K≤128, M equals to 8; when 128<K≤512, M equals to 16; when 512<K≤8192, M equals to 24; when K>8192, M equals to 32, wherein K and M are in unit of bits. determining, according to a pre-stored check code mapping relationship between the length K of the information sequence and the CRC check code length M, the CRC check code length M corresponding to the target information sequence, wherein in the check code mapping relationship, a CRC check code length M corresponding to an information sequence with a longer length K is greater than or equal to a CRC check code length M corresponding to an information sequence with a shorter length K; wherein the mapping relationship is as follows: when K≤128, M equals to 8; when 128<K≤512, M equals to 16; when 512<K≤8192, M equals to 24; when K>8192, M equals to 32, wherein K and M are in unit of bits.