A data processing method including receiving a data flow sent by an encoder side, where the data flow is a bit stream on which interleaving encoding is used, the data flow includes synchronization information, and the synchronization information is distributed in the data flow based on a first permutation interval, obtaining, from the data flow, first data information based on a first value interval and a first value length, where the first value interval is equal to the first permutation interval, and a difference between the first value length and a length of the synchronization information is less than or equal to a preset error value, and when a similarity between the first data information and the synchronization information exceeds a preset similarity threshold, performing de-interleaving on the data flow based on a start location of the first data information.