The present invention relates to the mobile communications field, and in particular, to a synchronization signal sending method. A network device obtains a first signal after performing discrete Fourier transform DFT and orthogonal frequency division multiplexing OFDM modulation, or OFDM modulation on a ZC sequence whose root index is 1; the network device obtains a second signal after performing DFT and OFDM modulation, or OFDM modulation on a conjugate sequence of the ZC sequence whose root index is 1; the network device generates a synchronization signal, where the synchronization signal includes the first signal and the second signal; and the network device sends the synchronization signal to a terminal device. By using this method, when there is a relatively large frequency offset between the terminal device and the network device, an M2M service requirement can still be met.