Embodiments of this application provide a random access method, a network device, and a terminal device. The random access method includes: receiving, by a terminal device, a system message that is sent by a network device on a first downlink carrier, where the system message includes first information required for performing random access on a first uplink carrier and second information required for performing random access on a second uplink carrier, a frequency of the first uplink carrier is higher than a frequency of the second uplink carrier, and a frequency of the first downlink carrier is the same as the frequency of the first uplink carrier; sending, by the terminal device, a random access request message on the first uplink carrier or on the second uplink carrier; and receiving, by the terminal device, a random access response message that is sent by the network device on the first downlink carrier. According to the random access method provided in the embodiments of this application, the terminal device can implement random access on the first uplink carrier or on the second uplink carrier, thereby improving a random access success rate and enhancing uplink coverage performance of the network device.