A method for implementing data mapping and transmission includes that: data to be transmitted is segmented into N code blocks, the N code blocks are divided into M code block groups (CBGs), and a difference between numbers of code blocks in any two CBGs being less than or equal to a preset value, and the M CBGs are mapped and transmitted on at least one transmission unit. The M CBGs include a first CBG and a second CBG, and a value of a parameter of information amount of the first CBG and a value of a parameter of information amount of the second CBG satisfy a preset condition; and the at least one transmission unit includes a first physical resource corresponding to the first CBG and a second physical resource corresponding to the second CBG, and the first physical resource is ahead of the second physical resource in time domain.