Fuente: WIPO "processing tomato" The invention discloses a polylactic acid nucleating agent with a plasticizing function as well as a preparation method and application thereof. The nucleating agent comprises tomato peel residues. The nucleating agent disclosed by the invention comprises the tomato peel residue powder with a lamellar structure characteristic, so that the crystallization property, the impact property and the hot working rheological property of the polylactic acid are improved, and the characteristic of complete biodegradability after being compounded with the polylactic acid is maintained. The tomato pomace powder is derived from naturally aired tomato pomace, the waste tomato pomace is dried and crushed into powder with a certain particle size to serve as a raw material of the nucleating agent, the nucleating agent has the advantages of being rich in raw material source, low in cost, easy to process and biodegradable, the problem of accumulation of a large amount of tomato pomace waste generated in tomato processing production is solved, and the production cost is reduced. Waste utilization is achieved, and the purposes of environmental protection, energy conservation and emission reduction are achieved.