Abstract: Space Science Experimental Platform (SSEP) is a multi-function experimental platform being developed as an alternative for traditional single-function experimental apparatus. This paper introduces the designs of heat transfer fluid loops in SSEP, and related design methods for some major equipment, including Avionics Air Assembly (AAA) fan, gas-liquid heat exchanger and cold plates. Suggestions for working fluid selection are also listed with the considerations of heat transfer efficiency and system safety. Preliminary analysis results, as well as the successful application of such designs in similar platforms developed by ESA and NASA, proved that fluid loop heat transfer technology, combined with complementary active and passive thermal control measures, can maintain the multi-function experimental platform and its payloads within their required temperature limits.