A service data processing method and apparatus is disclosed. A data frame is divided into code blocks with smaller granularity, and service data is mapped to a corresponding quantity of code blocks in the data frame based on a service requirement. In addition, the data frame is used to indicate a location of a code block carrying the service data. In one manner, a code block in a payload area of the data frame is divided into a data code block and an overhead code block, and the overhead code block is used to indicate a location of a data code block carrying the service data. In the another manner, an indication field is configured in an overhead area of the data frame to indicate a location of a code block that carries the service data and that is in the payload area of the data frame.