Combining with the practical situation of development roadway in broken surrounding rocks in Suncun Colliery of Xinwen Coal Mine Bureau,on the basis of study on the mechanism of floor heave of roadway,numerical simulations were made with FLAC2D on the displacement of roof to floor,the development of the plastic zone and tensile stress zone in surrounding rocks before and after reinforcing the floor of roadway.The in-situ observation indicated that for the roadway in soft rocks it is necessary to reinforce the floor,roof and two sides,but special attention should be also paid to the reinforcing of floor,so that the integral stability of surrounding rocks of deep roadway can be ensured.