The Ocean-1C satellite（HY-1C）is an operational application satellite serving the monitoring of ocean water color and temperature，coastal zones，and marine disasters and environment. It is an important source of ocean remote sensing data，which is of great significance for the assessment and correction of the SST observation data of Chinese HY-1C infrared radiometer in Southeast Asian waters. In this study，the quality assessment and improvement work of Chinese HY-1C satellite SST data in the Southeast Asian sea area is carried out based on multi-source satellite SST data and ARGO buoy measurement temperature data. The quality assessment results of the HY-1C SST data show that the mean bias，standard deviation and root mean square error of HY-1C during daytime are –0.73℃，1.38℃ and 1.56℃，respectively，and the nighttime data deviations are –0.95℃，1.57℃ and 1.83℃，respectively. Comparison of the data quality with other similar infrared radiometers reveals that the accuracy of the HY-1C SST data is lower than that of other infrared radiometers. Three correction methods，namely，monthly mean difference correction，SST subarea difference correction，and SST segmentation correction，are used to improve the data quality of HY-1C SST，among which the quality improvement of HY-1C SST subarea correction is the most obvious，with the standard deviation and the root mean square error close to 1℃，and the nighttime root mean square error reduced by about 0.8℃ compared with that before the correction，and the daytime and nighttime root mean square errors reduced by respectively 32.52%，and 42.04%.