A method (100) of producing a heat pipe includes the following steps: (1) inserting a mandrel (10) into a hollow metal casing (20) with a space formed between the hollow metal casing and the mandrel; (2) filling into the space with a slurry (40) comprised of powders; (3) solidifying the slurry in the space; (4) drawing the mandrel out of the hollow metal casing after the slurry is solidified; and (5) sintering the powders contained in the slurry to form the heat pipe (60) with a sintered powder wick (61) arranged therein. In the sintering step of the method, no mandrel is required. Thus, the problem that the mandrel is difficult to be drawn out of the hollow metal casing as suffered in the conventional art is effectively solved.