The invention discloses a device for increasing the reuse rate of purified water of a refinery plant, and a using method of the device, belonging to the technical field of purified water recovery of refinery plants. Filters are introduced into a purified water pipeline in the existing hydrogenation water injection water source; two stages of filtration facilities are added for improving the water quality of the purified water. One stage of filtration facility comprises two filters which can be switched; one of the two filters is started and the other filter is used for standby application during normal production; the filters are switched for washing at the fixed period; the two filters are respectively and internally provided with a filter screen wire mesh as a filter element, and the filter precision is greater than 25mu m; the differential pressure indication on an inlet and outlet pipeline of the first stage filter is used for displaying the differential pressure of the first stage filter; a built-in framework of the second stage filter is formed by a 304 stainless steel punched filter screen and an internal filter bag, and the filter precision is greater than 10mu m. The device provided by the invention increases the proportion of the purified water in hydrogenation water injection and improves the properties of the purified water in the hydrogenation water injection.