Abstract: Sebei gas field in Qaidam basin is a typical sandstone gas reservoir with multiple thin layers and loose sands. There are nearly 100 reservoirs from shallow to deep in the gas field. In order to realize efficient development and to improve reserves producing degree, multi-layer commingled production technology is applied in the gas field. In terms of the problems like interference between layers and unbalanced reserves producing resulted from the commingled production, a physical simulation method is proposed for the commingled production in this paper. Combined with numerical simulation, the main factors influencing the reserves producing degree of the gas reservoir during commingled production are discussed and the production performance under different formation pressures and different physical properties are systematically analyzed. Based on which, the favorable conditions for the commingled production are studied and a series of charts is established by taking permeability multiple ratio and pressure multiple ratio as evaluation parameters, which can be used to judge physical property and formation pressure of different gas zones, then to evaluate the interference degree of the commingled production and finally to provide a basis for the perforation combination optimization in the multi-layered gas reservoirs