The invention relates to foam liquid for drilling, in particular to strong inhibition type anti-collapse foam liquid for drilling, which is characterized by being prepared with the following components in parts by weight: 0.09-0.11 part of foam stabilizer, 0.36-0.44 part of foaming agent, 2.34-2.86 parts of anti-collapse agent, 2.7-3.3 parts of fluid loss additive and 94.51-93.29 parts of water. When complex situations such as formation water occur to gas drilling, the foam liquid of the invention can effectively improve the rock carrying capacity and the water carrying capacity and simultaneously protect the stability of the upper well wall. Laboratory studies shown that the foam liquid has high foaming capacity, the foaming capacity is more than or equal to 500 percent, the half-life is moderate, and the foam liquid can be easily controlled and is conducive to drilling engineering construction.