The invention discloses a clean production method of 1-(3,4-dichlorophenyl)-2-thiourea. The clean production method comprises a step of treating production wastewater of 1-(3,4-dichlorophenyl)-2-thiourea, wherein the treatment step comprises the following steps that (1) the production wastewater of the 1-(3,4-dichlorophenyl)-2-thiourea is subjected to pH value regulation by ammonia, then, separation is performed to obtain 3,4-dichlorophenyl and separating liquid, and the 3,4-dichlorophenyl is reused in the production step of the 1-(3,4-dichlorophenyl)-2-thiourea; (2) the separating liquid in the first step is sequentially subjected to vacuum concentration, crystallization and separation to obtain condensed water, ammonium chloride and crystal mother liquor, and the condensed water and the crystal mother liquor are reused in the production step of the 1-(3,4-dichlorophenyl)-2-thiourea. The clean production method of the 1-(3,4-dichlorophenyl)-2-thiourea provided by the invention has the advantages that the total resource recycling of the production wastewater can be realized, and the yield of the 1-(3,4-dichlorophenyl)-2-thiourea is improved to higher than 97 percent.