Abstract: In order to explore the damage characteristics and deformation and failure rules of coal and rock under uniaxial static and dynamic combined action,a separate Hopkinson pressure bar device is used to carry out laboratory tests of coal and rock dynamic characteristics,and a finite element simulation static and dynamic combined dynamic test is carried out.Under the conditions of 20%, 40%, 60% and 80% peak stress,the uniaxial impact compression tests of coal and rock with impact pressure of 0. 06,0. 08 and 0. 10 MPa are simulated. The influence of different static and dynamic combination conditions on the mechanical properties and failure mechanism of coal and rock is analyzed. The results show that the cracks mainly develop from the middle of the specimen and gradually extend to the whole specimen when the coal and rock are subjected to dynamic load,and the final failure form is fragmented. The superposition of the incident wave and reflected wave strain curves is consistent with the transmission wave strain curves,which satisfies the two assumptions of one-dimensional stress wave and stress uniformity. The dynamic stability and dynamic failure time of coal and rock are non-linear and positively correlated with the initial static load class. When the static load class reaches 50% of the limit strength of coal and rock,the load action will accelerate the dynamic failure of coal and rock. At the same static load level,with the increase of impact pressure,the time required for coal and rock samples to reach the ultimate instability state is significantly shortened.Compared with the static load,the dynamic failure time is longer,and the peak strength is higher.