A phase noise suppression method for a multiple-input multiple-output (MIMO) system with a plurality of co-reference channels includes: dividing the phase noise of each channel in the MIMO system into common phase noise and independent phase noise, and constructing a certain number of joint phase states for the independent phase noise; inserting a pilot sequence into the sent signal based on a preset cycle, obtaining the common phase noise based on the pilot at receiver, and performing compensation; and performing signal demodulation on each joint state of the independent phase noise, and comparing the posterior log likelihood values to select the optimal result to output. The above method can significantly improve the phase noise suppression performance of the MIMO system with a plurality of co-reference channels, thereby providing support for improving the system capacity by using MIMO technology.