The invention discloses an odor-resistant device for a sewer of a road for municipal engineering. The odor-resistant device comprises an odor-resistant decontamination tank. The odor-resistant decontamination tank is arranged in the sewer, a water inlet is formed in the upper portion of the odor-resistant decontamination tank, a sewer cover plate is mounted at the water inlet, a drain outlet is formed in the middle of a side surface of the odor-resistant decontamination tank and is connected with a blow-down pipeline, an odor-resistant isolation plate is further connected with the outer side of the drain outlet, the upper end of the odor-resistant isolation plate is connected onto the side surface of the odor-resistant decontamination tank by hinges, and a decontamination pool is arranged at the inner bottom of the odor-resistant decontamination tank. The odor-resistant device has the advantages that the odor-resistant isolation plate is in a closed state when sewage on the ground is not drained into the odor-resistant decontamination tank at ordinary times, and covers the drain outlet, so that sewage and odor in the blow-down pipeline can be prevented from being discharged; the odor-resistant isolation plate is opened under the effects of sewage pressures after the sewage is drained in the odor-resistant decontamination tank and the sewage level reaches a certain altitude, accordingly, the blow-down pipeline can be communicated with the odor-resistant decontamination tank, the sewage can flow into the blow-down pipeline, and partial sundries can precipitate at the bottom of the odor-resistant decontamination tank, in other words, the decontamination pool, and can be conveniently cleaned.