Wet compression technology reduces the temperature inside the compressor by spraying water droplets at the inlet of the compressor to improve the turbine output. This technology improves compressor performance and efficiency by reducing compression work and compressor exit temperature. Wet compression technology affects compressor aerodynamic performance depending on variables such as droplet sizes and mass flow rate. This analysis has concentrated on the aerodynamic performance with droplet diameter in wet compression technology. As a result, the centrifugal compressor applied with wet compression technology showed lower exit temperature and increased pressure ratio than the conventional centrifugal compressor. In addition, the compressor performance varied by droplet diameter, and the best performance was shown when the droplet diameter was 2㎛. These results confirmed that wet compression technology improves the performance and efficiency of centrifugal compressor.