This application provides a communication method in a dual-connectivity mode. In the communication method, maximum transmit power used by a terminal device to send a message corresponding to a main network protocol in a semi-persistent power sharing mode is maximum transmit power 2, maximum transmit power used by the terminal device to send a message corresponding to a secondary network protocol is maximum transmit power 3, the maximum transmit power 2 is less than theoretical maximum transmit power corresponding to the main network protocol, and the maximum transmit power 3 is greater than the theoretical maximum transmit power corresponding to the main network protocol.