Sulige gasfield is a typical fluvial tight sandstone gas reservoir. The effective reservoir of the gas reservoir is thin with various superimpose and complex structure. The reservoir has strong heterogeneity both in the horizontal and vertical and it is difficult to be finely described. As a result it is difficult to model the gas reservoir accurately. Either conventional deterministic or stochastic method can not make a satisfied sedimentary facies model because of their limitations when they were used alone，and the geological model obtained agrees poorly with the associated dynamic simulation. As a case from the Su6 infilling well experimental area in Sulige gasfield，an effective reservoir modeling method was built combining deterministic sedimentary facies modeling with stochastic sedimentary facies modeling to control and constraint gradually sedimentary facies modeling based on sedimentary microfacies study，effective reservoir size and distribution. The accuracy of geologic modeling could be improved through synthesizing advantages of the single conventional modeling method and being constrained by dynamic and static parameters. A history matching coincidence rate is 52.4%，which indicates that the new method can model the actual situation of the reservoir better.