The invention belongs to the field of lamp masks, and specifically discloses a ridge-surface hemispherical shell type optical face mask of an LED lamp. The ridge-surface hemispherical shell type optical face mask comprises an outer spherical shell, an inner spherical shell and a face mask bottom, wherein the structure from the center of the outer spherical shell to the periphery of the outer spherical shell is that a plurality of isosceles triangles which are uniformly distributed around the vertex are arranged at a first layer; a plurality of isosceles trapezoids which are uniformly distributed are arranged at all the layers from the second layer to the last layer; the bottom side of each isosceles triangle is connected with the upper bottom side of one isosceles trapezoid; the lower bottom side of each isosceles trapezoid except from the isosceles trapezoids at the last layer is separately connected with the upper bottom sides of the isosceles trapezoids at the next layer; the structure of the inner spherical shell is the same as that of the outer spherical shell; the dimension of the inner spherical shell is smaller than that of the outer spherical shell; the bottom of the inner spherical shell is connected with the bottom of the outer spherical shell through the face mask bottom; and the inner part of a part defined by the inner spherical shell, the outer spherical shell and the face mask bottom is made of a transparent optical material. The ridge-surface hemispherical shell type optical face mask can meet requirements of a large-power LED, and improves a utilization rate of luminous flux.