The invention discloses a plugging plate for a sealing head pipe nozzle of a water chamber of a steam generator. The plugging plate for the sealing head pipe nozzle of the water chamber comprises a support plate, an air bag, a control system and a connection pipeline, wherein the support plate comprises a left plate, a middle plate and a right plate, and the left plate and the right plate are connected with the middle plate through hinges; the air bag wraps the bottom surface of the support plate, extends along the side flange of the support plate, and is fixed to the side edges of the left plate and the right plate by fasteners; the air bag comprises three layers which are a drive sealing cavity, a secondary sealing cavity and a primary sealing cavity in sequence from one side facing thesupport plate to the other side; and the control system communicates with the air bag and an external gas source through the connection pipeline, and controls air inflation and air exhaust of the connection pipeline. The plugging plate for the sealing head pipe nozzle of the water chamber is foldable, thereby facilitating rapid installation and sealing, and three sealing cavities are formed, thatis, three safety backups are arranged, so that the probability of function failure of equipment is greatly lowered, and the safety of the equipment is improved; and the whole equipment is capable of being detached, installed and cleaned separately, long in service life, and capable of saving lots of cost.