The invention discloses an opening system for pressure relief windows. The opening system for pressure relief windows comprises a pressure relief window (1) arranged at the air inlet side of an air door wall (7), a pipeline (5) extending from the air return side to the air inlet side of the air door wall (7) is arranged above the air door wall (7), one end (close to the air inlet side) of the pipeline (5) is provided with a first fixed pulley (4), the two ends of a rope (3) respectively extend to the air inlet side and air return side of the air door wall (7) through the first fixed pulley (4) and the pipeline (5), and one end of the rope (3) at the air inlet side of the air door wall (7) is connected with a free end below the pressure relief window (1). According to the scheme provided by the invention, when an operator passes through an air door from the air inlet side of the air door wall, after an operation of pressure relief is implemented by opening the pressure relief window at the air inlet side of the air door wall by a handle at the air return side of the air door wall, the operator can open the air door and then passes the air door.