A data transmission method in type 1 channel access, comprising: receiving (S 102), by a terminal device, indication information sent by a network device, wherein the indication information is used to indicate a first time domain resource used by the terminal device to send first uplink transmission; and sending (S 103), by the terminal device, the first uplink transmission to the network device on the first time domain resource, and sending second uplink transmission to the network device on a second time domain resource, wherein the second time domain resource is a time domain resource determined by the terminal device based on the first time domain resource, the second time domain resource is earlier than the first time domain resource in time; wherein the first uplink transmission is uplink transmission that the network device schedules the terminal device to send, and the second uplink transmission is uplink transmission that is sent by the terminal device in a grant-free manner, characterized in that the indication information is further used to indicate a first frequency domain resource used by the terminal device to send the first uplink transmission; and the first time domain resource and the second time domain resource are consecutive in time when the first frequency domain resource comprises a full bandwidth resource on a carrier carrying the first uplink transmission; and the first time domain resource and the second time domain resource are inconsecutive in time when the first frequency domain resource does not comprise a full bandwidth resource on a carrier carrying the first uplink transmission. receiving (S 102), by a terminal device, indication information sent by a network device, wherein the indication information is used to indicate a first time domain resource used by the terminal device to send first uplink transmission; and sending (S 103), by the terminal device, the first uplink transmission to the network device on the first time domain resource, and sending second uplink transmission to the network device on a second time domain resource, wherein the second time domain resource is a time domain resource determined by the terminal device based on the first time domain resource, the second time domain resource is earlier than the first time domain resource in time; wherein the first uplink transmission is uplink transmission that the network device schedules the terminal device to send, and the second uplink transmission is uplink transmission that is sent by the terminal device in a grant-free manner, characterized in that the indication information is further used to indicate a first frequency domain resource used by the terminal device to send the first uplink transmission; and the first time domain resource and the second time domain resource are consecutive in time when the first frequency domain resource comprises a full bandwidth resource on a carrier carrying the first uplink transmission; and the first time domain resource and the second time domain resource are inconsecutive in time when the first frequency domain resource does not comprise a full bandwidth resource on a carrier carrying the first uplink transmission.