Air-dried unsaturated polyester resin and production method thereof

The invention discloses an air-dried unsaturated polyester resin and a production method thereof. The air-dried unsaturated polyester resin comprises the following raw materials by weight: 200-220 parts of dimer acid; 1200-1300 parts of tetrahydrophthalic anhydride; 700-750 parts of maleic anhydride; 1150-1200 parts of propylene glycol; 280-300 parts of neopentyl glycol; 1.150-1.25 parts of triphenyl phosphite; 0.5-0.6 part of a polymerization inhibitor QS-20; 1400-1500 parts of styrene; 0.5-1.5 parts of an antifoaming agent BYK-A555 and 0.4-0.6 part of a leveling agent BYK-307. The invention also discloses the production method of the resin.