Extraction dechlorination method for petroleum unpolymerized C5

The invention discloses an extraction dechlorination method for petroleum unpolymerized C5. The method includes: firstly adding the unpolymerized C5 raw material and an extractant into an extraction tower, conducting treatment by the extraction tower to obtain dechlorinated unpolymerized C5 with Cl less than or equal to 10ppm, treating the residual component by a resolving tower to obtain high chlorine unpolymerized C5 with an extractant content of less than or equal to 50ppm, discharging the residue which is mostly the extractant component from the bottom of the resolving tower and letting it re-enter the extraction tower for recycle through a feed pipeline. The method solves the problem of dechlorination of C5 petroleum resin as a low-end product, after dechlorination, the chlorine content is less than or equal to 10ppm, and the dechlorination efficiency is high. Compared with the traditional hydrodechlorination process, the method uses fewer equipment, is easy to operate, has low equipment requirement, prolongs the service life of the equipment, and has high safety grade.