Abstract: When the shallow coal seam is mined through the valley area，if there is a lack of key stra⁃ ta，it is easy to cause the instability of the overburden structure and induce the dynamic mine pressure. Based on the research background of the support crushing accident occurred during the 1305-2 working face of Zhujiamao Coal Mine passing through the first valley，the key strata position and support crushing mechanism were analyzed based on the field survey and theoretical derivation，and the dynamic load mine pressure prevention and control technology was proposed. The research shows that the main reason for the support crushing accident is that there is no lateral horizontal restraint force due to the local loss of the main key strata of the roof overburden rock，the " masonry beam " structure appears to slide and destabilize，and the mine pressure of the working face is induced in the form of dynamic load. Through mechanical derivation，it is concluded that reducing the periodic weighting step of the working face can effectively alle⁃ viate the dynamic mine pressure behavior，and the combined prevention and control technology of deep hole blasting and hydraulic fracturing is used to deal with the roof strata of the working face during the working face passing through the second valley. The final periodic weighting step is reduced from 18 m to 12 m，and no support crushing accident occurs，which ensures the safe production of the working face.

Key words: shallow coal seam, valley, dynamic mine pressure, support crushing accident