A data decoding method, performed by a computer device, is provided. The data decoding method includes obtaining coded data corresponding to a current to-be-decoded unit, obtaining a coding mode restriction type corresponding to the current to-be-decoded unit by decoding the coded data, determining a candidate coding mode set corresponding to the current to-be-decoded unit according to the coding mode restriction type, the candidate coding mode set comprising a block copy intra-frame coding mode, selecting a target coding mode from the candidate coding mode set, and decoding the current to-be-decoded unit according to the target coding mode, thereby obtaining corresponding decoded data.