The invention provides a signal processing method and device. The method comprises the following steps: selecting a specified constellation diagram version according to parameter information of a transmission signal, obtaining a first phase rotation angle corresponding to the specified constellation diagram version, selecting a second phase rotation angle according to preset information, and performing phase rotation for time domain symbols or frequency domain symbols of the transmission signal based on the first phase rotation angle and / or the second phase rotation angle, wherein the parameter information includes one or more of the following parameters: data types, modulation modes, time domain granularity of data duplication, constellation diagram versions of signaling configuration, and predefined constellation diagram versions. According to the signal processing method and device provided by the invention, the peak to average power ratio (PAPR) of the transmission signal can be effectively reduced, the problem of too high PAPR during signal transmission in related technologies can be solved, and thus the power amplifier efficiency of a transmitting terminal can be increased, the power consumption of the terminal can be saved, and the effects of reducing the terminal cost and ensuring the signal coverage of the system can be achieved.