Plastic processing method and processing system

A processing system of plastics, characterized in that the system comprises:

• a liquefaction unit, a viscosity reduction unit, a cracking reaction unit, and a separation unit;
• the liquefaction unit comprises an inlet for the plastic to be treated and an outlet for the liquefied plastic, and the liquefaction unit is configured to liquefy the plastic to be treated, preferably, the liquefaction unit has a rapid conveying mechanism so that the residence time of the plastic to be treated in the liquefaction unit is 5-30 minutes, for example, 5-20 minutes, 5-15 minutes;
• the viscosity reduction unit comprises an inlet for liquefied plastic, an outlet for liquid phase material and an outlet for dry gas, and the viscosity reduction unit is configured to perform a heat treatment on the liquefied plastic to reduce its viscosity to form a liquid phase material;
• the cracking reaction unit comprises an inlet for cracking raw material and an outlet for reaction product;
• the inlet for cracking raw material is communicated with the outlet for liquid phase material of the viscosity reduction unit, and the cracking reaction unit is configured to perform a cracking reaction treatment on the liquid phase material;
• the separation unit includes a separation inlet, an outlet for dry gas, an outlet for liquefied gas, an outlet for gasoline fraction, an outlet for diesel fraction and an outlet for gas oil fraction;
• the separation inlet is communicated with the outlet for reaction product of the contact-cracking reaction unit, the separation unit is configured to perform a separation treatment on the reaction product.