The invention relates to an expansion method of a reactor upgraded from a photocatalytic waste water degradation catalyst interception mechanism, and belongs to the technical field of waste
water treatment. The method aims at solving a series of problems that a catalyst runs off, the single tank volume is small, a
degradation reaction endpoint is difficult to distinguish, a catalyst aggregator cannot be dissipated forcefully in situ, catalyst aggregation cannot be perceived immediately, preventive measures on water burst of a
quartz cavity are insufficient, etc. in the prior art. The method mainly comprises the steps of restraining microwaves to irradiate a designated area only, expanding a reactor dimension, improving air supply intensity for a key
degradation reaction area, progressively intercepting the catalyst with an external cascaded three-stage back flushing filter, forcefully dissipating a catalyst aggregator in situ with ultrasonic
waves from the bottom of the reactor, cleaning a
quartz tube incidentally, monitoring a reaction course with an
ozone sensor, automatically turning off a related power supply at the degradation endpoint, actively checking a catalyst aggregation trend, and the like.