The invention discloses a vulcanizing machine provided with die locking stress application mechanisms, which comprises upper and lower cross beam bodies, left and right wallboards, die opening and closing cylinders and the like, and also comprises two sets of die locking stress application mechanisms symmetrically arranged on the left and right of the upper cross beam body. A die locking stress application cylinder and a guide seat of each set of die locking stress application mechanism are fixed on the upper cross beam body; the inner end of a wedge-shaped bolt inserted into the guide seat is connected with a piston rod of the die locking stress application cylinder; and the wedge-shaped bolt is opposite to a wallboard hole before vulcanizing and is inserted into the wallboard hole during vulcanizing. The bottom surface of the wedge-shaped bolt is horizontal, the near inner end of the upper surface is a plane, and the near outer end is an inclined plane. The wallboard hole is matchedwith the wedge-shaped bolt. The maximum height of the wallboard hole is smaller than that of the wedge-shaped bolt. The upper ends of the left and right wallboards are interconnected by connectors. After a die is closed, the die locking stress application cylinder drives the wedge-shaped bolt to be inserted into the wallboard hole and then continuously applies the stress, the extruding expansion force of the wedge-shaped bolt to the wallboards is decomposed into an upward pretightening force, and the wallboards, an upper cross beam, the die and a lower cross beam form a closed force system. Astress application cylinder is saved, so the vulcanizing machine has a compact structure and low cost.