Method for evaluating gas production property of gas reservoir at horizontal section of shale gas horizontal well

The invention relates to a method for evaluating the gas production property of a gas reservoir at the horizontal section of a shale gas horizontal well. The method comprises the following steps: determining a root-mean-square productivity index IAAOF of a work area and the length Lx of the gas reservoir to be evaluated at the horizontal section of the shale gas well according to well tested information of the shale gas horizontal well in the work area; estimating a total amount VFx of fracturing fluid for hydro-fracturing of the gas reservoir to be evaluated at the horizontal section of the shale gas well, and a use amount of a supporting agent; calculating the open flow capacity QAOFx of the gas reservoir to be evaluated at the horizontal section of the shale gas well by using a model QAOFx=IAAOF X Lx X (VFx+VSx); evaluating the gas production property of the gas reservoir to be evaluated at the horizontal section of the shale gas well according to QAOFx; and outputting calculation and evaluation results. T