Disclosed are a method for transmitting a signal, a terminal device and a network device. The method comprises: a terminal device determining a time domain position, in a first transmission cycle, of a synchronization signal block burst of a cell where the terminal device is located; and the terminal device receiving, according to the time domain position of the synchronization signal block burst in the first transmission cycle, a synchronization signal block sent by a network device. The method, the terminal device and the network device in the embodiments of the prevent application can reduce the computation complexity of the terminal device, reduce the detection time and save on the power consumption.