The inside blowout preventer is the necessary tool assigned by the international Association of Drilling Contractors (IADC) in drilling operations. When the blowout is happened during drilling tools are coming out of hole, the inside blowout preventer is needed, because the drill pipes as much as possible shall be put into hole again. The inside blowout preventer in picture 1 is the new developed product which has been used to substitute import product and used in some big oilfields in China. After being tested and used by the consumers, it has fully proved that the features and construction for the product has caught up the international levels.