The subway tunnel project is usually in a long-term humid environment, which requires high grouting material behind the wall. It should not only undergo the erosion of mud water, but also have good fluidity and fillability. According to the characteristics of subway engineering, a new type of foaming agent was prepared by using anionic surfactant to modify the mother liquor of animal protein and adding alcohol to stabilize the foaming agent. The foaming ability and bubble stabilization ability of mother liquor were improved successively by being mixed with different polar macromolecular substance. The results show that the appropriate foaming agent and foaming stabilizer can improve the strength, toughness and viscosity of the foam, and reduce the sedimentation and bleeding. When the foaming group is 0.8% and the foaming group is 0.15%, the foaming agent and foaming stabilizer have the best foaming and foaming stabilizer performance, and the prepared grouting material has excellent structure and performance. Micro -structure analysis found that when the water binder ratio increased from 0.40 to 0.48, the amount of foam is large and connected pores are easily generated, which makes the uniformity of the pore size deteriorate and the settlement increases.