Development of shale gas by using horizontal well fracturing measure has become a trend in shale gas development all over the world. However, because shale gas presents an occurrence state in shale substrate and artificial fractures and has a unique seepage, its production capacity analysis is more complicated. On the basis of conventional fracturing horizontal well productivity research theory, conducted is analysis on shale gas reservoir adsorption, desorption, gas high-speed non-darcy flow in fractures and coupling of fractures with shaft and applied is the method of conformal transformation for derivation and obtained is the semi-analytical model for fracturing horizontal well productivity analysis. Example analysis results show that horizontal wellbore pressure drop has less effect on shale gas reservoir fracturing horizontal well productivity, horizontal wellbore pressure drop can be neglected if yield is low. Along with increase of reservoir thickness, fracture half length, fracture diverting capacity, number of fractures and substrate concentration difference inside and outside, shale gas reservoir fracturing horizontal well production will increase gradually, but increase trend will be more and more gentle and tend to be stable in the end. Therefore, fracture parameters shall he optimized in shale gas development in order to achieve the optimum development effect.