The invention discloses a method for shale-gas-well storing-layer brittleness comprehensive evaluation. The method includes the following steps that to-be-measured shale samples are subjected a triaxial compression testing experiment, and a complete stress-strain curve is obtained; a brittleness drop coefficient R, a stress depreciation coefficient P and a softening modulus M are calculated, the brittleness indexes corresponding to the brittleness drop coefficient R, the stress depreciation coefficient P and the softening module M are subjected to normalization processing respectively, and a comprehensive brittleness index Bd is obtained; correction is carried out according to a Bd calculation model, the corrected brittleness index Bd<3> serves as an objective function, parameters such as a shale dynamic elastic modulus E in well logging data serve as independent variables, function regression is carried out, a multi-regression function Y of the Bd<3> is obtained and substituted into different-layer-section storing-layer well logging parameters, and the comprehensive brittleness indexes of different well-section storing layers are obtained. According to the method, the whole condition of shale damaging is considered, and the brittleness characteristics of shale can be comprehensively responded; meanwhile, the brittleness of different-depth, different-confining-pressure and different-well-section storing layers is analyzed by combining shale-gas-well logging information, and the adaptability is high.