The digital communication system based on PSK modulation is widely used in the practice of wireless communication engineering. Due to various conditions, the PSK digital communication signal received from the actual engineering system is difficult to obtain in teaching and scientific research, while the PSK modulation simulation data can be generated by itself. On the basis of mastering the communication principle and simulation technology, this paper uses Matlab to simulate digital communication signal sources such as BPSK, DPSK, QPSK, 8PSK, π/4-DQPSK, OQPSK, etc. It can flexibly set parameters such as modulation system, working frequency, transmission code rate, sampling frequency and channel characteristics, and generate data files with specified formats as required. It can be used as a training and testing sample for modulation mode identification software. In addition, this paper combines the spectral line parameter characteristics such as modular square spectrum, square spectrum, fourth power spectrum, eighth power spectrum, etc., and combines constellation diagram and eye diagram to identify and verify the modulation system of digital communication signals based on PSK modulation.