Disclosed are a method for random access, and a terminal device and a network device. The method comprises: where the random access of a first terminal device fails, the first terminal device determining, according to a trigger condition of the random access, the length of a waiting time before the random access is initiated again; and the first terminal device re-initiating the random access according to the length of the waiting time. The method, the terminal device and the network device provided in the embodiments of the present applicant can improve the flexibility and system performance of a communication system.