The invention discloses an airbag canopy jettison mechanism which comprises a canopy, a left fuselage, a right fuselage and an airbag. The airbag is arranged in the position, close to one side of the right fuselage, of the upper end face of the canopy. A canopy opening of the airbag is downward. One end of the canopy is in lap joint with the left fuselage, and the other end of the canopy is connected with the right fuselage through spring lock devices. The spring lock devices comprise sleeves, lock bolts, lock pins and pretightening devices of the lock pins. The bolt ends of the lock bolts are in longitudinal sliding connection with guide holes in the lower portions of the sleeves, and the bolt handle ends of the lock bolts are connected with the canopy. The lock pins and the pretightening devices are horizontally arranged in the sleeves. A semispherical groove is formed in one side of the bolt end of each lock bolt. Pin ends of the lock pins are semispherical. When the semispherical pin ends are inserted into the semispherical grooves of the lock bolts, the canopy is locked. When the semispherical pin ends are separated from the semispherical grooves of the lock bolts, the canopy is unlocked. The airbag is adopted as a power source; a power device is omitted; the complexity of the mechanism is lowered; a spring lock and a clamping block are combined, and the mechanism is simple and reliable, low in cost, convenient to dismount and mount and low in mass.