The invention discloses a fireproof structure of an elevator landing door. The fireproof structure comprises an elevator door plate and a sill, wherein at least two grooves are formed in the sill in parallel, a raised guide rail is arranged between two adjacent grooves, and the guide rail continuously extends in the door opening and closing direction of the elevator door plate; a guide groove which is matched with the guide rail is formed in the lower end of the elevator door plate, the portions, on two sides of the guide groove, of the lower end of the elevator door plate are respectively embedded into the grooves in both sides of the guide rail of the sill, and a guide part which is matched with the guide rail is arranged in the guide groove. According to the fireproof structure, the raised guide rail is arranged between the bottoms of the grooves of the sill, the guide part which is matched with the guide rail is arranged in the door plate, the guide rail is used for guiding the door plate and preventing the door plate from falling off, and additionally, the both sides of the lower end of the door plate are integrally embedded into the grooves of the sill, so that the fireproof performance of the door plate is improved, and the integral strength and anti-unhooking capability of an elevator door system are increased.