It is very important to systematically study the NMR characteristics of the shale core sample before the NMR logging technology can be used in the development of the shale gas reservoir. This paper studies the NMR characteristics, the NMR porosity, the movable fluid T_2cutoff and other NMR properties of the shale rock sample. The experimental results demonstrate that the shale T₂ spectrum can be divided into three types, the single peak T₂ spectrum, the two peak T₂ spectrum containing one isolated right peak and the two peak T₂ spectrum containing continuous left and right peaks. The T₂ relaxation of the shale is mostly less than 10ms. The fracture porosity is only about 9.16% of the total pore space. The surface area per unit volume of the shale gas reservoir ranges mainly from 3.59 to 80.51μm^-1. The shale NMR porosity is generally less than its conventional porosity. The average error is about 22.33%. The movable fluid T_2cutoff value is in the range from 3.87 to 16.68ms and its average value is 8.29ms. The free gas saturation of the shale gas reservoir obtained from the centrifugal experiment is about 9.72%.