China has a wide area of multi-year and seasonal frozen regions. Special geological and climatic conditions must be considered for engineering construction and mining of mineral resources in these regions, and the stability of slope in cold regions is worth studying. In order to study the rock mechanics mechanism of slope instability under low temperature, Marble samples are drilled from the slope of Yulong Copper Mine in Tibet. With the help of SHPB experimental system with low temperature control system, dynamic compression and tensile mechanics experiments are carried out on rock samples under normal temperature and dry conditions, normal temperature and adequate water conditions and low temperature freezing conditions, to explore the influence of temperature and water content on rock dynamic mechanical properties. The experimental results show that :(1) The average uniaxial dynamic compression and tensile strength of frozen rock samples at -20 ℃ are increased compared with those at room temperature under the joint influence of water ice phase transformation at low temperature and rock matrix cold shrinkage. Under the four strain rates, the compressive stress increased by 1.24, 1.37, 1.41, 1.69 times, and the tensile stress increased by 1.11, 1.25, 1.20, and 1.05 times, respectively. (2) Strain rate effect also exists in rock dynamic strength at low temperature; (3) Under the same strain rate, the dynamic impact crushing time of frozen marble is the longest, and the decrease rate is the fastest with the increase of strain rate. Under the same strain rate, the crushing energy consumption of frozen rock sample is smaller than that of normal temperature, and increases little with the change of strain rate.