A data transmission method and apparatus are provided. The method includes: sending, by a terminal device, a message 1 including a random access preamble to a first network device; receiving DCI and a message 2 including downlink data scheduled by the DCI from the first network device, wherein the DCI and/or the message 2 include/includes first information, which is used to schedule ACK/NACK feedback information of the message 2; and sending the ACK/NACK feedback information to the first network device based on the first information. According to the application, the first information is used to schedule the ACK/NACK feedback information, therefore the terminal device may send the ACK/NACK feedback information of the message 2 to the first network device in an MT-EDT scenario based on the first information, thereby improving robustness of transmission of the downlink data in the message 2.