Quaternary ammonium salt clay stabilizer as well as preparation method and application thereof

The invention provides a quaternary ammonium salt clay stabilizer as well as a preparation method and application thereof. The quaternary ammonium salt clay stabilizer comprises a polymer generated by self-polymerization of dimethyl diallyl ammonium chloride; the weight-average molecular weight of the quaternary ammonium salt clay stabilizer is lower than 20,000, the rotation radius of the quaternary ammonium salt clay stabilizer is 0.4-0.6 nm, the cation degree of the quaternary ammonium salt clay stabilizer is 3-4mmol/g, the anti-swelling rate of the quaternary ammonium salt clay stabilizer is greater than 85%, the washing resistance rate of the quaternary ammonium salt clay stabilizer is greater than 80%, and the temperature resistance of the quaternary ammonium salt clay stabilizer is greater than or equal to 160 DEG C. The quaternary ammonium salt clay stabilizer is not only suitable for high-permeability rock cores, but also can enter pores to play a role, and is suitable for low-permeability rock cores