A horizontal well one-way valve comprises an upper joint, an upper baffle ring, a lower baffle ring, a spring, a valve ball, a seal ring, a valve base, a valve base sleeve and a screen plug. The valve base, the valve base sleeve and the screen plug are connected with the upper joint in turn, the valve ball is arranged on the valve base and the valve base sleeve, the upper baffle ring, the spring and the lower baffle ring are mounted on the valve ball in the upper joint inner cavity in turn. The utility model has advantages that oil sleeves are communicated, an overflow well blowout can be prevented, the midway plugging of a packer can be prevented, the sealing of the horizontal well is reliable, the valve, a screen tube and a pipe plug can form an integrated design, the structure is compact, and the cost is low, and the utility model can be widely applied to the horizontal downhole operation process for oil extraction.