This application provides a data transmission method and apparatus. The method includes: receiving, by a first network node, first indication information sent by a second network node, where the first indication information is used by the first network node to determine first duration, and the first duration is duration from receiving a first data packet by the first network node to sending the first data packet by the first network node; and sending, by the first network node, the first data packet based on the first indication information. The data transmission method and apparatus provided in embodiments of this application help ensure that a communications network transmits a data packet based on a duration requirement.