The invention relates to a micro-reaction system and a method for synthesizing rubber anti-scorching agent CTP. The system consists of a micro-heat exchanger, a micro-reactor and a stirring tank reactor in series. The synthesis method comprises the following steps of: pre-cooling dicyclohexyldisulfide in a micro heat exchanger, and then continuously reacting with chlorine gas in a micro reactor togenerate cyclohexyl sulfinyl chloride; cyclohexyl sulfinyl chloride continuously flowing out of the micro-reactor and entering the stirring tank reactor to be condensed with the sodium phthalimide salt added in advance to generate the reaction solution containing N-cyclohexylthiophthalimide (CTP), refining by water separation to obtain CTP product. Among them, the reaction temperature in the micro-reactor is -20-15 DEG C, and that reaction time is 0.01 second-1.5 minute; the reaction temperature in the stirring tank reactor is -10-10 DEG C, and that reaction time is 10-60 minutes. The reaction time of the chlorination step of the invention is greatly shortened, and the total yield of the two-step reaction is higher than 93%, which is 3-4% higher than the prior production technology.