A data transmission method, comprising: determining (S210), by a terminal device according to a first rule, a first type of transmission or a second type of transmission as a target type of transmission when the terminal device determines, according to first configuration information, to perform the first type of transmission on a target transmission resource and determines, according to second configuration information, to perform the second type of transmission on the target transmission resource, wherein the first type of transmission is sidelink transmission between the terminal device and another terminal device, and the second type of transmission is uplink transmission or downlink transmission between the terminal device and a network device; and performing (S220) data transmission with the target type of transmission on the target transmission resource, wherein the first rule comprises: determining the first type of transmission as the target type of transmission when priority information of the first type of transmission meets a first preset threshold; and determining the second type of transmission as the target type of transmission when the priority information of the first type of transmission does not meet the first preset threshold, and wherein the method is characterised in that : when the first type of transmission or the second type of transmission comprises transmission of a feedback channel, determining priority information of the feedback channel according to an attribute of a logical channel corresponding to a data channel corresponding to feedback information in the feedback channel. determining (S210), by a terminal device according to a first rule, a first type of transmission or a second type of transmission as a target type of transmission when the terminal device determines, according to first configuration information, to perform the first type of transmission on a target transmission resource and determines, according to second configuration information, to perform the second type of transmission on the target transmission resource, wherein the first type of transmission is sidelink transmission between the terminal device and another terminal device, and the second type of transmission is uplink transmission or downlink transmission between the terminal device and a network device; and performing (S220) data transmission with the target type of transmission on the target transmission resource, wherein the first rule comprises: determining the first type of transmission as the target type of transmission when priority information of the first type of transmission meets a first preset threshold; and determining the second type of transmission as the target type of transmission when the priority information of the first type of transmission does not meet the first preset threshold, and determining the first type of transmission as the target type of transmission when priority information of the first type of transmission meets a first preset threshold; and determining the second type of transmission as the target type of transmission when the priority information of the first type of transmission does not meet the first preset threshold, and wherein the method is characterised in that : when the first type of transmission or the second type of transmission comprises transmission of a feedback channel, determining priority information of the feedback channel according to an attribute of a logical channel corresponding to a data channel corresponding to feedback information in the feedback channel. <EOS>