Abstract: The seabed geothermal research has become a common component of integrated marine geological survey nowadays and high requirements are raised to the technical performance of instruments for seabed measurement. Based on the FY1, the self-contained miniature temperature measurement recorder independently developed by Guangzhou Marine Geological Survey, a new type of self-contained miniature temperature measurement recorder, FY2 in abbreviation, was developed after summarization of previous practicce data and survey experiences. In order to verify the performance of the FY2, efforts have been devoted to the instrument calibration and the comparison of the FY2 to the FY1 in laboratories under a constant temperature flume as well as in the deep water area on the northern slope of the South China Sea. Results show that the resolution of the FY2 is higher than 0.0001 ℃, and the precision is higher than ±0.0015 ℃. The seabed geothermal flow value of the measuring point is 78 mW/m²; indicating an excellent performance of the new equipment. The new equipment also has high efficiency, and may provide strong technical support for the research of seabed geothermal flow.