Method for deacidification on paper material by utilizing nano calcium hydroxide-containing subcritical fluid

The invention discloses a method for deacidification on a paper material by utilizing nano calcium hydroxide-containing subcritical fluid. The method comprises the following steps: (1) taking and putting to-be-treated paper into a high pressure-resistant extraction kettle, and firstly cleaning by using subcritical fluid under the conditions that the pressure is 5.0 to 12.0 MPa and the temperatureis 30 to 50 DEG C; (2) maintaining the conditions, adding a nano calcium hydroxide deacidifying agent in the high pressure-resistant extraction kettle under the existence of the subcritical fluid, andcarrying out deacidification treatment on the paper by utilizing the subcritical fluid and the deacidifying agent in common. According to the method disclosed by the invention, a subcritical fluid technology is applied to deacidification of the paper material, the deacidifying agent can effective permeate into a cellulose structure of the paper material, solvent residue does not exist, and the treated paper material is no