A data transmission method includes: receiving a first indication message from a base station, the first indication message including first information indicating a PDCP packet duplication function and at least two transmission entities configured for a radio bearer (RB) by the base station; setting a transmission function corresponding to the RB as the PDCP packet duplication function according to the first indication message; setting a transmission entity corresponding to the RB according to the at least two transmission entities indicated in the first indication message; setting a present state of the PDCP packet duplication function, the present state including an active state and an inactive state; and performing data transmission according to the present state and the transmission entity.