This application provides a relay communication method, a communication apparatus, and a communication system, to effectively improve efficiency of accessing a cell of a network device by a remote terminal. The method is applied to a communication system including a first terminal, a second terminal, and a third terminal, and the first terminal is a relay device used by the second terminal to access a network device. The method includes: The first terminal receives system information from the network device, and determines, based on the received system information, that the second terminal fails to camp on a first cell of the network device. The first terminal sends first indication information to the second terminal, where the first indication information indicates to break a sidelink between the first terminal and the second terminal, or the first indication information indicates that the second terminal fails to camp on the first cell.