A light distribution method for a COB module LED street lamp lens capable of illuminating 3 or 5 lanes, wherein the light emitted by a COB module LED light source is firstly refracted by a drop-shaped refraction lens and then refracted secondarily by a light distribution curved surface lens to achieve an optimal irradiation effect; the section profile line of the drop-shaped refraction lens in the direction perpendicular to the road, namely, the Y-Y direction, is composed of an inclined long elliptic arc and a short arc, the section profile line of the drop-shaped refraction lens in the road extending direction, namely, the X-X direction, is semicircular, and the curved surface of the drop-shaped refraction lens is formed by sweeping the section profile line in the Y-Y direction along the section profile line in the X-X direction; the light distribution curved surface lens has different angles of asymmetrical light distribution in the Y-Y direction and the X-X direction, the section profile line of the light distribution curved surface lens in the Y-Y direction and an optical axis OZ form a polarization angle, the light distribution method being characterized in that the light distribution to single light satisfies the following condition: θ 2 = tan − 1 θ 1 − Ψt tanΦr + 90 ° − θ 1 tanΦ1 90 ° − Ψt wherein θ 2 is an included angle between emergent light and the optical axis, and the optical axis is a straight line which passes through the center point O of the COB module LED light source and is perpendicular to a bottom surface; θ 1 is an included angle between incident light and the optical axis; Ψ t is an included angle between an axis OT connecting a point farthest from a point O on the Y-Y section profile line of the light distribution curved surface lens with the point O and the optical axis OZ; Φ 1 and Φ r are respectively included angles between marginal emergent light on the left and the right of the light distribution curved surface lens and the optical axis OZ; the section profile line in the X-X direction is a symmetrical saddle-shaped curve, and the light distribution of the light distribution curved surface to the single light satisfies the following condition: δ 2 = tan − 1 δ 1 90 ° ⋅ tan 74 ° in the formula, δ1 is an included angle between the incident light OU and the optical axis OZ, and δ2 is an included angle between the emergent light VW and the optical axis; the light distribution curved surface lens is formed by sweeping the section profile line in the Y-Y direction along the section profile line in the X-X direction. wherein θ 2 is an included angle between emergent light and the optical axis, and the optical axis is a straight line which passes through the center point O of the COB module LED light source and is perpendicular to a bottom surface; θ 1 is an included angle between incident light and the optical axis; Ψ t is an included angle between an axis OT connecting a point farthest from a point O on the Y-Y section profile line of the light distribution curved surface lens with the point O and the optical axis OZ; Φ 1 and Φ r are respectively included angles between marginal emergent light on the left and the right of the light distribution curved surface lens and the optical axis OZ;