Abstract: Small scale thermal bus for satellite thermal control,can realize three-dimensional arrangement of hot devices,and be independent with the heat radiating area.By this way,the integration intensity was improved,and the cooling requirements of large payloads integrated by function were met.A new concept about two-phase fluid loop was presented,which used capillary pump instead of mechanical pump to realize a small scale two-phase thermal bus without moving parts,high reliability and long life.The capillary pump in this loop required to be heated actively to force fluid flow,and consume some power as well.How to reduce pump′s input power is the key for capillary pumped two-phase thermal bus(CPTPTB) to get practical.Analysis and experiment indicated that thermoelectric cooler(TEC) had high coefficient of performance for heating in small temperature difference.It shows that it is more economical to heat up capillary pump with TEC than with direct electric heater.