For the modulation recognition problem of Orthogonal Frequency Division Multiplexing (OFDM) signals and Single Carrier Linear Digital (SCLD) modulation signals at low Signal-Noise-Ratio (SNR),a recognition method based on Synchrosqueezed Wavelet Transform (SWT) is proposed.The SWT algorithm is used to extract the wavelet ridge and wavelet frame information of the signal,then the variance of wavelet ridge after differential and median filtering is used to distinguish OFDM signals and single carrier signals,and the ridge and frame features are used to accomplish the intra-class recognition.Simulation results show that in Rayleigh-additive white Gaussian noise channel with low SNR,the proposed method has a good recognition effect.