The self-sealing floor drain skillfully adopts counter weight principle of dynamic balance, when the water flows into the floor drain to reach a certain amount, the stainless steel slice at the bottom will be opened under the water gravity. When the water stop flowing, the sealing gasket can completely and automatically sealed due to lump on the other side. Thus, it can effectively stop the flow backward of dirty water and harmful gas in the sewer. Meanwhile,it is a good way to block hazardous substances, like the harmful bugs, so that you can have a safe and healthy indoor environment.