The oilfield LD27-2 is an ordinary heavy oil reservoir. Oil wells breakthrough early and water cut rising rapidly in cold production. In order to study the feasibility of steam soaking and optimize gas injection plans, it analyzes reservoir heterogeneity. The experimental studies on viscosity-temperature relationship, crude distillation, dissolution gas decreasing viscosity, cyclic steam stimulation were carried out. The results show that the serious heterogeneous and higher oil-water viscosity ratio can lead to sharp water cut increase in cold production. While the temperature is higher than 100℃, the viscosity decreasing trend slowed down with the increase of temperature. Because of high initial boiling point, there is almost no the steam distillation effect when the temperature is lower than 200℃. Dissolving gas into oil can make the oil volume coefficient increase and viscosity decrease. Although the gas injection volume of steam stimulation can not reach good result in the initial stage, the cycle oil production increases with injection cycles and tends to peak during the third cycle. The research results could provide certain reference for the optimization of steam stimulation development.