The invention relates to a production method of polyvinyl chloride paste resin, in particular to a method for improving production efficiency of micro-suspension polyvinyl chloride paste resin. The method comprises the following steps: emulsifying an initiator, an emulsifier, a co-emulsifier, a vinyl chloride monomer and desalted water, then adding into a polymerization kettle, reacting at the temperature of 40-60 DEG C, and replenishing the vinyl chloride monomer after the reaction is carried out for 30-60 minutes. Compared with the prior art, the method has the advantages that fouling degree is reduced, production efficiency is improved, consumption of auxiliaries is reduced and particle size and particle size distribution can be controlled by virtue of amount of the monomer added in the production process and adding rate; and the problem that material homogenizing time is relatively long during the current polyvinyl chloride paste resin production is solved, the particle size of the homogenized material meets process requirements, and stable emulsion liquid drops and appropriate product particle size range and particle size distribution range can be still guaranteed after the polyvinyl chloride monomer is replenished, so that homogenizing time is shortened, and production efficiency is improved.