Parallel Flat Gate Valve without Diversion Hole is designed with good sealing property, small ON/OFF operating moment upon full pressure difference and with easy maintenance and long service life, and therefore it is extensively used for delivery pipelines of natural gas, petroleum and petroleum products, chemical industry, environment protection, etc., blow-down systems and storage devices of oil and gas, acting as a start-stop device. It is applicable for the pipelines free of pipe cleaning.