A bug-proof and odor-proof drainage device includes a cover, a base, and a connecting pipe connecting plural bases of different bug-proof and odor-proof drainage device. The cover has plural draining holes arranged in intervals. A capping is disposed on the bottom surface of the cover. The base has a through hole surrounded by a wall part extending upward. The base is embedded in floors of bathrooms and kitchens and connected to a draining pipe through the through hole and also connected to different bases by the connecting pipe. Water flows into the base, and then circuitously sinks to flow over the wall part and rises along the wall part, thereby flowing into the draining pipe from the through hole, such that a portion of water is stored within the base for preventing bugs and odor from entering through the draining holes.
