Method and system for dechlorinating waste plastic oil

The invention relates to a waste plastic oil dechlorination method and system.The method comprises the steps that waste plastic oil and light oil enter a first reactor and make contact with a first catalyst for a dechlorination reaction, and a first mixed material is obtained; feeding the first mixed material and an optional heavy oil raw material into a second reactor, and contacting with a second catalyst for catalytic cracking reaction to obtain a second mixed material; the second mixed material enters a first separation device for first separation, and a spent catalyst and reaction oil gas are obtained; the reaction oil gas enters a second separation device to be subjected to second separation, and dry gas, liquefied gas, gasoline fraction, light diesel oil fraction and heavy oil fraction are obtained; the light diesel oil fraction enters a hydrogenation device to be in contact with a hydrogenation catalyst for hydrogenation reaction, and hydrogenated light diesel oil is obtained; the hydrogenated light d