This application provides a signal transmission method and a communications apparatus. The method includes: receiving, by a terminal device, configuration information, where the configuration information is used to configure the terminal device to transmit M signals in a first time unit, the terminal device has N antenna panels, M is an integer greater than or equal to 1, and N is an integer greater than or equal to 2; and transmitting, by the terminal device, at least one of the M signals based on first information by using at least one of the N antenna panels. According to embodiments of this application, the terminal device can select a panel based on the first information and select a signal that needs to be transmitted.