A furnace door knife edge for a coke furnace belongs to the technical field of coke furnace structures. The furnace door knife edge for a coke furnace comprises a knife edge main body which is provided with a rectangular mesopore in the centre; an upright wall vertical to the plane of the knife edge main body is arranged at the same side and the inner edge joint part of the knife edge body; upper and lower upright walls vertical to the plane of the knife edge main body are respectively arranged on the outer edge and two sides of the knife edge main body in a conjoined way; and the distance from the outermost end of the upright wall to the plane of the knife edge main body is greater than the distance from the outermost end of the upper right wall to the plane of the knife edge main body. The invention can use stainless steel to set and mold, reduces procedures such as bending, has good sealing effect, avoids the phenomena of smoking and gas leakage in coking plants, makes great contribution to environmental protection and reduces the production cost of an enterprises.