This application provides a power control method including: receiving, by a second node, radio resource control (RRC) from a first node, where the RRC includes a power control parameter set configured for the second node, the power control parameter set includes a power control index, and the power control index is determined based on a transmission mode or a transmission capability of the second node; receiving downlink control information (DCI) including power control index indication information used to: when the first node schedules the second node, indicate a value of a power control index that is for uplink transmission and that is for the second node; determining a transmit power based on the power control index indication information and the power control parameter set; and sending a signal at the determined transmit power.