A transmission direction configuration method carried out by a terminal device, comprising: receiving,, initial configuration information from a network device through a radio resource control, RRC, signaling, wherein the initial configuration information comprises a correspondence between at least one index value and at least one corresponding transmission directions configuration of an indexed list of transmission directions configuration; receiving,, first indication information sent based on a first parameter by the network device through a physical downlink control channel, PDCCH, wherein the first indication information comprises an index value of the at least one index value; wherein the at least one transmission directions configuration of an indexed list of transmission directions configuration is used to indicate a configuration of uplink and/or downlink transmission directions, the configuration is used to describe types, a number, and distribution of resource elements comprised in each period in a time duration that is indicated by a second parameter and that starts from the time point indicated by a third parameter, wherein the time duration includes N periods, wherein N is a positive integer, the resource element is a resource that is obtained through division based on a resource granularity, the resource granularity comprises a time domain granularity, the time domain granularity comprises an orthogonal frequency division multiplexing, OFDM, symbol, the types of the resource elements comprise an uplink resource element, a downlink resource element, and a switch resource element between the downlink resource element and the uplink resource element, a transmission direction of the uplink resource element is an uplink direction, and a transmission direction of the downlink resource element is a downlink direction; and performing,, information transmission or a configuration operation based on the configuration, indicated by the first indication information, of the uplink and/or downlink transmission directions. receiving,, initial configuration information from a network device through a radio resource control, RRC, signaling, wherein the initial configuration information comprises a correspondence between at least one index value and at least one corresponding transmission directions configuration of an indexed list of transmission directions configuration; receiving,, first indication information sent based on a first parameter by the network device through a physical downlink control channel, PDCCH, wherein the first indication information comprises an index value of the at least one index value; wherein the at least one transmission directions configuration of an indexed list of transmission directions configuration is used to indicate a configuration of uplink and/or downlink transmission directions, the configuration is used to describe types, a number, and distribution of resource elements comprised in each period in a time duration that is indicated by a second parameter and that starts from the time point indicated by a third parameter, wherein the time duration includes N periods, wherein N is a positive integer, the resource element is a resource that is obtained through division based on a resource granularity, the resource granularity comprises a time domain granularity, the time domain granularity comprises an orthogonal frequency division multiplexing, OFDM, symbol, the types of the resource elements comprise an uplink resource element, a downlink resource element, and a switch resource element between the downlink resource element and the uplink resource element, a transmission direction of the uplink resource element is an uplink direction, and a transmission direction of the downlink resource element is a downlink direction; and performing,, information transmission or a configuration operation based on the configuration, indicated by the first indication information, of the uplink and/or downlink transmission directions.