Abstract: To control the unsafe acts and further reduce the accident rate, we identified 122 unsafe acts of 88 cases of major and serious coal and gas outburst accidents based on accident causation "2-4" model, and classified unsafe acts as violation operation, violation action, violation commanding and non-violation. The classification study showed that the top three types with the highest frequency were violation action (43%), violation operation (35%) and violation commanding (21%); the unsafe acts with highest frequency respectively corresponding to the top three types were "not eliminating outburst signs", "blasting in the working face with outburst danger", "arranging workers working in outburst dangerous working face"; violation operation(99%) and violation action（99%） involved the most accidents while the percentage of accidents influenced by violation commanding had large variation at different time and in different mine with different gas grades. Based on the results, we analyzed the causation of main unsafe acts for various types and propose the corresponding control measures.