The present invention relates to a method of reducing catalyst pollution during the driving process of a methanol to olefin reacting device. The method mainly solves the problem in the prior art of serious catalyst pollution during the driving process. The method comprises the steps as follows: a molecular sieve catalyst with coke is returned to a reaction area to react with raw materials continuously; after the average coke quantity of the catalyst in a reactor takes 2.0 percent to 6.0 percent in weight, torch oil is injected into a regenerator, the regenerator is heated to 500 DEG C to 700DEG C immediately; the catalyst is circulated into the regenerator, the coke burns and produces heat; the injection of the torch oil is stopped, catalyst circulation between the reactor and the regenerator is established; after the temperature of the regenerator is stabilized between 600 DEG C and 700 DEG C, an auxiliary air chamber is stopped touse. The method solves the problem well by a technical proposal with the steps and can be applied in the industrial production of light olefin.