The utility model relates to a well well head water injection device specifically says to relate to a well water injection is with sealed single current valve. The utility model discloses a water supply connector, the housing body and the UNICOM's cover that link to each other with this water supply connector still are provided with the valve body at the housing body inner chamber, and valve body one end is the valve rod, and the other end is the case, and the case outside is provided with matched with disk seat with it, disk seat outer wall and housing body's inner chamber sealing contact. The utility model discloses can effectively prevent oil field injected water refluence, can use all water injection well well heads, the application is wider, be particularly useful for the loose water injection well that easily shakes out in stratum, can reduce the water injection well and return and tell the sand number of times, reduce the well of lying, guarantee the good water injection effect of water injection well.