The invention discloses a tight sandstone anhydrous gas reservoir gas-bearing capacity evaluation method, and solves the technical problem of low tight sandstone anhydrous gas reservoir gas-bearing capacity evaluation precision in the prior art. The method mainly comprises the following steps: sequentially calculating a shale content curve Vsh, an effective porosity curve phi e, a pure rock neutron curve CNL1, an apparent sandstone skeleton hydrogen content index curve CNL2 and a gas content evaluation index parameter GASFG curve, and finally carrying out gas content evaluation according to the gas content evaluation index parameter GASFG curve. According to the method, the excavation effect of the natural gas on the neutron logging curve is fully utilized to quantitatively characterize the gas-bearing index parameters, and the technical problem in the prior art that the tight sandstone anhydrous gas reservoir is difficult to accurately evaluate the gas-bearing property of the reservoir under the condition that stratum water and other data are lacked is effectively solved through classification evaluation. Practice proves that the technology not only can accurately evaluate the gasbearing capacity of the tight sandstone anhydrous gas reservoir, but also can effectively identify the high gamma reservoir, so that an accurate exploration method is provided for oil and gas exploration.