The invention discloses an automatic dumping device for hyperbaric chamber cell culture reagents. A chamber door of the hyperbaric chamber is arranged at the top; the side of the chamber body is provided with an electrical penetration piece; an electric control system includes a drive mechanism positioned outside the chamber and a two-phase hybrid stepping motor located in the chamber, and is used to connect the signal lines outside the chamber to a signal terminal of the motor through the electrical penetration piece; a transmission mechanism connector connects the motor shaft of the two-phase hybrid stepping motor with a liquid storage mechanism, the connector drives the liquid storage mechanism to rotate for the same angle, so as to successfully pour reagents in one group of test tubes into the cell culture dish; a liquid storage rack is provided with a plurality of test tube place positions, two connected groups of liquid storage rack have a certain angle, and place positions of different groups of test tubes are separated. The device provided by the invention has reasonable structure, can operate normally in the hyperbaric chamber automatically dump cell culture reagents, and add a variety of reagents at the same time or add different reagents at different time, so as to improve the experimental efficiency.