Embodiments of the present disclosure relate to the field of communications technologies, and provide a radio bearer reconfiguration method, a radio bearer establishment method, user equipment, and a base station. The method includes receiving, by a UE, a radio bearer reconfiguration indication sent by abase station, where the radio bearer reconfiguration indication includes a radio bearer identifier and a target configuration parameter, the radio bearer identifier indicates a target radio bearer that needs to be reconfigured, and the target configuration parameter corresponds to a configuration item of the target radio bearer that needs to be reconfigured; releasing, by the UE, the target radio bearer; and transmitting, by the UE, signaling and/or data on the corresponding target radio bearer according to the target configuration parameter.