Hydrodynamic drop-in tool of bridge plug

The utility model provides a hydrodynamic drop-in tool of a bridge plug. Big threads at the lower part of a diverting joint are connected with a primary hydraulic cylinder; small threads at the lower part of the diverting joint are connected with the upper part of a pressure transmitting inner pipe; a connecting rod is arranged at the lower part of the pressure transmitting inner pipe; a pressure separating joint is fixed at the upper part of the connecting rod; a primary piston is positioned between the primary hydraulic cylinder and the pressure transmitting inner pipe; the outer wall of the primary piston is matched with the inner wall of the primary hydraulic cylinder; the upper inner wall of the primary piston is matched with the outer wall of the pressure transmitting inner pipe; a secondary piston is arranged below the primary piston; the outer wall of the secondary piston is matched with the lower inner wall of the primary piston; the inner wall of the secondary piston is matched with the outer wall o