Abstract: Theoretical research status of mechanism of coal and gas outburst was summarized. Typical examples of similar materials of gas-bearing coal and simulation experiment device of coal and gas outburst were analyzed. Deficiency of the research of mechanism of coal and gas outburst and simulation experiment was pointed out，namely, theory research results of mechanism of coal and gas outburst are more qualitative description, lack quantitative, unified and complete theoretical system; the existing outburst simulation test systems and devices can not accurately simulate the outburst phenomena under the influence factors of geological structure, ground stress, coal strength, gas content and construction process, and the accuracy of the mechanical loading system, gas filling system and testing system of the test equipment needs to be further improved; the experimental operation and convenience of the test instrument are not enough, and the reproducibility of the test needs to be improved; the data analysis system of test instruments is not perfect. The development trend of mechanism research of coal and gas outburst and simulation experiment was prospected: the simulation experiment of coal and gas outburst must conform to the similarity theory, and the research of simulation test instrument of coal and gas outburst is an urgent demand for the breakthrough of mechanism research.