The present invention relates to the technical field of waste plastic recycling and reuse, and discloses a paint cleaning agent for waste plastic surfaces and a preparation method thereof. The cleaning agent comprises the following raw materials in weight percentage: 10—18% triethanolamine, 10—18% sulfur-containing organic compound, 7—15% ethoxylated alkylguanidine-amine complex, 10—18% sodium silicate, 5—12% sodium tripolyphosphate, 5—9% potassium hydroxide, 1—5% butyl cellosolve, 1—3% accelerator, 1—3% thickener, and the balance being water. The invention uses triethanolamine and sulfur-containing organic compounds to replace chlorinated alkanes as the main solvent in traditional paint removers, which is less harmful to human bodies and the environment, does not damage waste plastic substrates, has a low boiling point, is non-volatile, and reduces cost. The invention has good cleaning performance, thorough paint removal, low cost, low environmental pollution and convenient use.

Area Code: CN

Application Number: CN201410250792.8