Based on measured rock pressure and experimental data under thick watered loose bed of Wanbei mining area,dimorphism and mutation characteristics of ultrathin bedrock working face roof are discussed.

• 以皖北矿区厚含水松散层下超薄基岩开采工作面实测矿压资料与实验数据为依据,论述了超薄基岩工作面顶板的风化变异特征。