A method for greatly increasing the irradiation range of a street lamp or a high-pole lamp, wherein firstly, a COB module LED area light source is adopted as a light source; secondly, the LED area light source is firstly put into an incident concave surface to be covered by the same, so that the LED point light source is primarily refracted by the incident concave surface; thirdly, a light-distribution free curved surface is further arranged to cover the incident concave surface, so that the light ray primarily refracted by the incident concave surface is subsequently refracted by the light-distribution free curved surface to deflect by a large angle; after two refractions, an included angle between a position, perpendicular to an extension direction of a road, of the peak intensity and an optical axis ranges from 60 to 75 degrees and a light distribution angle in a direction in accordance with the extension direction of the road ranges from 120 to 150 degrees, whereby the illumination of one single COB module LED point light source to at least 6 lanes and illumination at an interval of at least 35m or long-distance illumination of a high-pole lamp are realized, characterized in that the coordinate value of each point (x,y) on a section profile line, extending in the direction perpendicular to the extension direction of the road and passing the COB module LED point light source, of the light-distribution free curved surface is determined by the following light distribution condition of one single light ray: θ 2 = − tan − 1 tan ξ 1 − α + 90 ° 180 ° ⋅ tan ξ 1 + tan ξ 2 Formula, wherein θ2 represents an included angle between an emergent ray and an optical axis OZ when an included angle between an incident ray OP and the optical axis OZ is α; OP represents the light ray OP emitted from the center point O of the COB module LED and incident into the incident concave surface; OZ represents an axis passing the center point O of the COB module LED and perpendicular to a mounting bottom surface thereof; a refracted ray PQ passes the light-distribution free curved surface for light distribution and is emergent as a light ray QS after light distribution; -ξ1 and ξ2 represent the maximum deflection angles expected to be obtained at the maximum light distribution angle of a marginal ray when the incident angle α is -90 degrees and +90 degrees, and the absolute values of the maximum deflection angles range from 60 to 75 degrees; the light distribution angle θ2 of the deflected emergent ray QS falls into a range of -ξ1 to ξ2; the positive and negative signs of the angles herein are defined as follows: a light ray deflecting toward the left of the optical axis OZ is negative, while a light ray deflecting toward the right of the optical axis OZ is positive; the numerical area of α ranges from -ξ1 to ξ2; the section profile line, extending in the direction perpendicular to the extension direction of the road and passing the COB module LED point light source, of the incident curved surface is composed of a segment of inclined elliptical arc A-B-C and a segment of arc C-D; the long axis of the elliptical arc A-B-C is OC, while the short axis thereof is OB; the value of the OC is 1-1.5 times the diameter of the area light source; the ratio OC/OB of the long axis to the short axis is between 1.2-2.5; the short axis OB has an inclination angle and an included angle between the short axis OB and the optical axis OZ is τ of which the numerical area ranges from 15 to 20 degrees; the arc is tangent with the inclined elliptical arc; the diagonal lines OL and OF, on a side close to A, of the incident concave surface are longer, while the diagonal lines OJ and OH, on a side close to D, of the same are shorter, and the ratio OL/OJ ranges from 1.1 to 1.3; the incident concave surface and the light-distribution free curved surface are formed by scanning the sectional curve along a curve determined according to the following condition: θ 1 = tan − 1 β 90 ° ⋅ tan ψ Formula, wherein ψ represents the maximum light distribution angle of the edge ray required when the incident angle β of the incident concave surface is +/-90 degrees; the light distribution angle θ1 falls into a range from the included angle of the optical axis and +/-ψ; the positive and negative signs of the light angles are defined as the same herein: the light ray deflecting toward the left of the optical axis OZ is negative, while the light ray deflecting toward the right of the optical axis OZ is positive.