Abnormal sound in the region near the stern cabin that was observed during the sea trial of a ship has been diagnosed as propeller singing according to the stern vibration and noise signals measured during the sea trial and the process and analysis of the collected data. In this regard, the elimination method is then proposed combined with the generation mechanism of the propeller singing. The propeller after trimming is then tested and verified. The results show that the method is reasonable and effective, which can provide reference for ship designers and repairmen.