Abstract: Pisha sandstone is widely distributed over the Ordos Plateau in Inner Mongolia, China. This loose rock layer is prone to soil erosion, due to the small overburden thickness, low pressure, low degree of rock formation, and inter-sand cementation. Fortunately, Pisha sandstone can serve as the main body to prepare the Pisha sandstone geopolymer cement composite soil using alkali excitation. The composite soil can also be applied to the channel lining for environmental protection in the cold areas of northern China, where the impact load usually happens, such as ice cream, and sandy water flow. In this study, the dynamic mechanical properties of Pisha sandstone geopolymer cement composite soil were investigated under various impact loads. A test was also carried out using Φ80 mm Split Hopkinson Pressure Bars (SHPB) with the air pressures from 0.04 to 0.3 MPa for various strain rates, thereby exploring the kinetic properties of Pisha sandstone ground aggregate cement composite. The results showed that the strain rate of Pisha sandstone geopolymer cement composite soil increased significantly, with the increase of impact air pressure, whereas, the growth rate decreased after the strain rate exceeding 161.69 s-1. Specifically, the dynamic modulus of elasticity of composite soil was relatively stable and grew less with the increase of strain rate when the strain rate was less than 64.67 s-1, whereas, the dynamic modulus of elasticity grew rapidly with the increase of strain rate, when the strain rate was greater than 64.67 s-1. A significant parameter, the dynamic increase coefficient (the ratio of dynamic strength to static strength) was also selected to evaluate the dynamic performance of cement soil. As such, the dynamic increase coefficient presented a linear relationship with the logarithm of strain rate, when the strain rate was less than 64.67 s-1, whereas, a nonlinear relationship with the logarithm of strain rate was found, when the strain rate was greater than 64.67 s-1. Furthermore, the continuous fracture was observed to break into several small pieces in the soil specimens under the impact load, where the degrees of fragmentation varied significantly with the impact load. Subsequently, a standard square-hole sieve of 0.63-26.5 mm was used to screen the particles of fragmented soil samples. Fragmentation characteristics of composite soil were established from the perspectives of mechanics and energy. The correlation was also established between various impact loads and the average block size, as well as the fractal dimension of Pisha sandstone fragments. Specifically, the average block size of fragmented specimens decreased as a power function, whereas, the fractal dimension first decreased and then increased, with the increase of strain rate and energy absorption flux density. A cut-off point appeared when the energy absorption flux density was 29.08 J/(s•m2), where the fractal dimension was the smallest. When the fractal dimension was smaller than the cut-off point, the fractal dimension decreased with the increase of strain rate and energy absorption flux density, whereas, when it was larger than the cut-off point, there was an increasing power function relationship with the fractal dimension. This finding can provide a strong theoretical reference for the application of Pisha sandstone geopolymer cement composite soil in specific engineering.