The invention provides a method for drawing dual cones on a preformed rod. The method is characterized by including the steps of firstly, preheating, to be specific, fixing the preformed rod by two clamps on an operating platform to ensure that the preformed rod is arranged at the horizontal plane, and turning on a blow
torch to burn positions where the cones are drawn out until surface glass is in a melting state; secondly, carrying out N drawing stages, to be specific, a first drawing stage, namely, slowly moving the clamps when the surface glass of the preformed rod is in the melting state and then stopping until the distance between the left clamp and the right clamp is increased to a
set distance, a second drawing stage, namely continuing heating the positions, with the maximum reducing, of the preformed rod by the blow
torch, and then moving the clamps to repeat the operation of the first step, repeating the previous steps until completing drawing of the Nth stage; further, turning off the blow
torch, placing the position, to be drawn, of the preformed rod, in a holding furnace, cooling slowly for a certain time,
cutting off from the finest drawing position by a
glass cutter, moving the two sections of preformed rod with the cones formed by drawing out of the holding furnace, and cooling the same for stand-by application.