How to efficiently weaken the impact danger of hard coal (coal rock) is a key problem that needs to be solved urgently in the field of impact ground pressure prevention and control, and solution immersion provides new ideas by regulating the coal rock structure and the energy accumulation-release process. In order to explore the influence of different immersion media, sodium chloride solution concentration and soaking time on the impact danger of coal rock, select coal rock samples to be soaked in pure water and 10%, 20%, 30% NaCl solution for 10 d, 20 d, 30 d respectively, and then carry out a uniaxial compression test and determine the peak value. Strength, shock energy index, elastic energy index, dynamic destruction time, energy release rate, damage factor and longitudinal wave velocity and other parameters are combined with the national standard impact tendency evaluation method for comprehensive characterization, and the microstructure evolution characteristics are analyzed by scanning electron microscopy (SEM). The results show that pure water immersion can also weaken the impact danger of coal rock to a certain extent, but the overall effect is weaker than that of NaCl solution treatment. Compared with pure water, the weakening of impact-related energy indicators in NaCl solution is more significant, the improvement of the national standard impact tendency level is more obvious, and its effect is "fast irst and then slow" The law of marginal decrease. The evaluation results of comprehensive multiple indicators and national standards can be obtained. Under the condition of 20% concentration and 20 d immersion, the impact risk of coal rock is the largest reduction and the stability is the best, which is the best combination within the range of the parameters of this test. SEM observations show that pure water mainly triggers the expansion of the primary microcracks of coal rock and the initial relaxation of the pore structure, while NaCl solution further promotes the penetration of microcracks and the enhancement of pore connectivity, resulting in a decrease in longitudinal wave velocity, an increase in damage factor, and changes the post-peak destruction and energy release process, so as to achieve impact risk. The danger is more effective in weakening. The research results can provide test basis and engineering reference for the selection of immersion media and parameter optimization.