Abstract: To improve the development effect of the thermal recov- ery of dense oil in Kelamayi oil field,study on composite steam stimulation in 9~(7+8) block is performed.Method combi- ning physical modeling with digital analog is utilized to the study on mechanism of composite steam stimulation,the se- lection and evaluation of composite synergist in different vis- cosities of crude oil,the laboratory evaluation of edge- wa- ter encroachment of composite stimulation core,the injection mode of composite steam stimulation,and the optimization of injection parameters.Laboratory evaluation and forecas- ting shows hat the composite stimulation technique is effec- tual to increase recovery ratio at the medium to later stage of thermal recovery for dense oil.