Abstract: In view of the present research situation of coal and gas outburst accidents at home and abroad, basing on the coal and gas outburst accident of Yixin Coal Mine of Hegang Mining Area, we analyze the coal and gas outburst accident causation which includes geostress, tectonic coal and methane, combine with the tectonic feature of Hegang Mining Area and tectonic stress field in eastern Heilongjiang. Supported with the tectonic stress and the chain of destruction of methane expansion, the positive correlation between tectonic coal thickness and intensity of outburst is dicoverd. It concludes that coal and gas outburst accident of Yixin Coal Mine is resulted by the comprehensively effect including tectonic stress, teconic coal and methane.