The invention discloses a vehicle-mounted curve rail lubricating agent lateral spraying device. The vehicle-mounted curve rail lubricating agent lateral spraying device comprises a height position adjusting pipe and a lateral spraying nozzle, wherein the height position adjusting pipe is fixed to a rolling stock axle box; a horizontal adjusting pipe is arranged in the position, close to the end portion, of the horizontal part of a bent pipe and can be adjusted in the axial direction on the horizontal part of the bent pipe; the horizontal adjusting pipe is connected with a vertical positioning sleeve of a round pipe structure; a positioning groove is formed in the lateral wall of the upper portion of the vertical positioning sleeve; an axial positioning pipe is arranged in an inner hole of the vertical positioning sleeve; an oil spraying pipe is arranged inside the axial positioning pipe; the upper end of the oil spraying pipe is connected with a petrol pump; the lower end of the petrol pump is connected with the lateral spraying nozzle; a spout of the lateral spraying nozzle corresponds to the elongation position of an outer rail of a curve rail; a radial positioning pin is arranged on the outer wall of the positioning pipe and matched with the positioning groove. The friction stressed portion is accurately and effectively lubricated and coated, abrasion of the friction portion is reduced, the service life of the rail is prolonged, consumption of lubricating materials is reduced, and waste is reduced.