The invention discloses a parking mechanism of an automatic gearbox. The parking mechanism comprises a parking mechanism housing, wherein a parking gear is arranged in the parking mechanism housing; aswing arm is arranged on the parking mechanism housing in a hinged mode through a hinge shaft; a convex pawl which is in embedded type fit to a groove area of the parking gear is arranged on the swing arm; and a spring is arranged between the swing arm and the parking mechanism housing. During parking, an operating handle is pulled to a gear P, and the convex pawl on the swing arm is embedded into the groove area of the parking gear, so that parking is realized; if a vehicle still moves when the convex pawl is embedded into the groove area of the parking gear, a toothed part of the parking gear is matched with the convex pawl in a contact and resisting mode, and an extruding and moving action of an elastic resisting mechanism pauses and even retracts, so that an impact phenomenon due to the fact that the convex pawl is forcibly embedded into the groove area of the parking gear is avoided. The parking mechanism provided by the invention can realize reliable parking; and meanwhile, safeand reliable matching of parts in the parking mechanism is guaranteed, so that the service life of the mechanism is prolonged.