Abstract: In order to solve the problem of floor heave in soft rock roadway with large section in deep mine, taking the 11302 working face air return of ChaHasu coal mine as the research object, firstly, the failure law of roadway floor heave was analyzed through field tests: There were zero displacement point and zero strain point at the bottom of roadway, the strata at the bottom of the roadway were divided into tensile strain rise zone, tensile strain drop zone and compressive strain drop zone from the surface downward, the distance between zero stress point and zero displacement point from the floor of the roadway was 1.32M and 1.68m respectively. Secondly, the influence of surrounding rock strength, surrounding rock stress and support form on floor heave of the roadway is analyzed, and on the basis of the above, the control technology of changing floor coal pillar size, optimizing roadway support parameters and local grouting is proposed. Finally, the engineering practice shows that the floor heave of roadway has been effectively controlled by adopting corresponding technical measures, and has good technical and economic benefits.