The utility model provides a multiphase flow experimental simulation mechanism that ventilates of entrying, including conical gas collection cabin, install the round ring type seal at conical gas collection cabin tip, install at conical gas collection cabin tip and be located the inboard airtight apron of round ring type seal, with the airtight apron center fixed connection's of department piston rod and the cavitation ware of being connected with the piston rod other end, the conical gas collection cabin tip outside still is provided with hollow cylinder mesa, said hollow cylinder mesa upwards be provided with six at least air vents week, and the interval between air vent and the air vent equals, the piston rod is located inside the hollow cylinder mesa. The utility model discloses outside vent line can be effectively reduced to the experiment and the interference in flow field, the validity of experimental simulation is guaranteed, with the help of the high-pressure encapsulated situation who realizes the closing plate in gas storage storehouse, open the gas storage storehouse with the help of the impact load effect of entrying simultaneously and realize effectively ventilating when entrying