Data packet retransmission by a radio link control (RLC) protocol entity of a transmit end is described herein. The retransmission includes sending a target sequence number and a first data packet to a MAC entity of the transmit end and recording a quantity of times the target sequence number is transmitted to the MAC entity of the transmit end at an RLC layer. In accordance with receiving the target sequence number and a negative acknowledgement that are sent by the MAC entity, obtaining the RLC layer transmission count corresponding to the target sequence number. In accordance with determining the RLC layer transmission count is less than an RLC layer transmission threshold, sending a retransmission instruction based on the first data packet to the MAC entity. In accordance with a retransmission condition at the RLC layer being met, the RLC entity of the transmit end triggers retransmission at the RLC layer.