Abstract: Based on the excavation and heading period, the elastic energy accumulated in the coal and rock masses would initiate mine pressure bump and the acc umulated energy value would be related to the excavation time and space. In order to define the factors and the primary and secondary relation affected to the elastic e nergy accumulation during the engineering excavation, taking the“7.16"Mine Pressure Bump Accident occurred in Chengshan Mine as a case, the paper analyzed and studied the three factors of the excavation time, the goaf above seam and the roof strength affected to the elastic energy accumulation. With the energy calculation and extraction, the FLAC3D was applied to obtain different factors affected the elastic energy distribution. The results showed that the above three factors all would affect th e elastic energy accumulation in the coal and rock masses. According to the influence degree of the energy distribution by each factor, the sequence from high to low W ould be the goaf above coal seam, the roof strength and the excavation time, the goaf above coal seam were the main control factor of the occurred accident.