Preparation method of acidically-decomposable high-temperature-resistant gel blocking agent

The invention relates to a preparation method for preparing an acidically-decomposable high-temperature-resistant gel blocking agent by adopting modified bentonite as a raw material. The preparation method comprises two portions, i.e. modification of bentonite and preparation of gel blocking agent. Specifically, the preparation method comprises the following steps: modifying the bentonite by using sodium hydroxide, Na2CO3 and water, mixing the modified bentonite, acrylamide, 2-acrylamide-2-methyl propyl sulfonic acid, non-ion surfactant, a cross-linking agent and an initiator, and performing the reaction under certain conditions, thus obtaining the gel blocking agent. The preparation method has the beneficial effects that the strength, the flexibility and the water-absorption expansion capacity are good, the performance can be maintained in an environment of 150 DEG C, and the gel has an acidic decomposition property that is not possessed by other gel blocking materials. The gel blocking agent can be acidical