Abstract: To solve the problem of easy collapse hole in soft coal seam, a new method of using foam concrete to support hole wall in borehole to prevent drilling collapse is proposed. Different samples were prepared by selecting aluminum powder, sodium bicarbonate and hydrogen peroxide as test foaming agents, and then the applicability of the samples was investigated from three angles of porosity, compressive strength and heat. The results showed that: the porosity of samples prepared with aluminum powder as foaming agent was 47.84%, the porosity of samples prepared with hydrogen peroxide as foaming agent was 43.27%, the porosity of samples prepared with sodium bicarbonate as foaming agent was 17.36%, and the highest compressive strength of samples prepared with sodium bicarbonate as foaming agent was 2.41 MPa, the 3-day compressive strength of the sample prepared with hydrogen peroxide as foaming agent was 1.98 MPa, the compressive strength of the 3 sample prepared with aluminum powder as foaming agent was 1.47 MPa, the compressive strength of three samples was more than 1 MPa for 3 days, and the requirement of supporting hole wall in the borehole was basically satisfied, and during the foaming process of aluminum powder, the slurry temperature rises from 19.3 ℃ to 36.4 ℃,which can not meet the requirements of downhole use; hydrogen peroxide is most suitable as the use of drilling hole foam concrete foaming agent.