The invention discloses a waste gas treatment system for a chemical plant incinerator. The waste gas treatment system comprises a supporting frame, evenly distributed supporting legs are fixedly mounted at the bottom of the supporting frame, an incinerator body is fixedly mounted at the top of the supporting frame, a combustion chamber is disposed in the incinerator body, a preheating chamber communicated with the combustion chamber is fixedly mounted on one side of the incinerator body, a smashing box is fixedly mounted at the top of the preheating chamber, a blower is fixedly mounted on theright side of the incinerator body, and an exhaust pipe arranged at the position of an air outlet of the blower penetrates the side wall of the incinerator body and is communicated with the combustionchamber. The waste gas treatment system can fully recycle heat contained in waste gas discharged out of the incinerator and can reduce energy waste; besides, through cooperative use of a purificationbox and a plurality of treatment boxes, the waste gas after waste heat utilization can be purified, dust, particulate matter and harmful gas ingredients in the waste gas are removed, the gas temperature is reduced, so that the surrounding environment can be protected, and the waste gas treatment system is conducive to the protection of people's health and is safer and more convenient to use.