A sidelink data transmission method, comprising: obtaining, by a terminal device, first configuration information, wherein the first configuration information is used to indicate to transmit a first sidelink transmission channel on a target transmission resource; obtaining, by the terminal device, second configuration information, wherein the second configuration information is used to transmit to transmit a second sidelink transmission channel on the target transmission resource; and sending, by the terminal device, either the first sidelink transmission channel or the second sidelink transmission channel on the target transmission resource according to a preset rule, wherein the preset rule comprises: according to a comparison result between first parameter information of first data to be sent on the first sidelink transmission channel and second parameter information of second data to be sent on the second sidelink transmission channel, sending, by the terminal device, the first sidelink transmission channel or the second sidelink transmission channel on the target transmission resource, and wherein the preset rule comprises, if the first data to be sent is feedback information for the first sidelink data, the first parameter information is priority information of the first sidelink data, the second data to be sent is second sidelink data, and the second parameter information is priority information of the second data: if a priority of the first sidelink data is higher than a priority of the second sidelink data, sending, by the terminal device, the first sidelink transmission channel on the target transmission resource; or, if the priority of the first sidelink data is lower than the priority of the second sidelink data, sending, by the terminal device, the second sidelink transmission channel on the target transmission resource. obtaining, by a terminal device, first configuration information, wherein the first configuration information is used to indicate to transmit a first sidelink transmission channel on a target transmission resource; obtaining, by the terminal device, second configuration information, wherein the second configuration information is used to transmit to transmit a second sidelink transmission channel on the target transmission resource; and sending, by the terminal device, either the first sidelink transmission channel or the second sidelink transmission channel on the target transmission resource according to a preset rule, wherein the preset rule comprises: according to a comparison result between first parameter information of first data to be sent on the first sidelink transmission channel and second parameter information of second data to be sent on the second sidelink transmission channel, sending, by the terminal device, the first sidelink transmission channel or the second sidelink transmission channel on the target transmission resource, and wherein the preset rule comprises, if the first data to be sent is feedback information for the first sidelink data, the first parameter information is priority information of the first sidelink data, the second data to be sent is second sidelink data, and the second parameter information is priority information of the second data: if a priority of the first sidelink data is higher than a priority of the second sidelink data, sending, by the terminal device, the first sidelink transmission channel on the target transmission resource; or, if the priority of the first sidelink data is lower than the priority of the second sidelink data, sending, by the terminal device, the second sidelink transmission channel on the target transmission resource. if a priority of the first sidelink data is higher than a priority of the second sidelink data, sending, by the terminal device, the first sidelink transmission channel on the target transmission resource; or, if the priority of the first sidelink data is lower than the priority of the second sidelink data, sending, by the terminal device, the second sidelink transmission channel on the target transmission resource.