Photoresist resin and preparation method thereof

The invention is suitable for the technical field of photoresist, and provides a photoresist resin and a preparation method thereof. The method comprises the following steps: dissolving a photoresist resin monomer and an initiator in a solvent to obtain a monomer solution; placing the monomer solution in a nitrogen environment, and heating the monomer solution at a high temperature in a stirring state until the temperature of the monomer solution is higher than 100 DEG C; introducing oxygen to promote polymerization reaction of the photoresist resin monomer to obtain a reaction solution; and cooling the reaction solution, and carrying out precipitation, separation and drying treatment to obtain the photoresist resin. In the process of preparing the photoresist resin, oxygen is introduced under a high-temperature condition and forms peroxy bonds with the photoresist resin monomer, so that the peroxy bonds are broken at high temperature to form new free radicals, the polymerization speed of the photoresist resi