The invention provides a paper document deacidification device and method. The device comprises a controller, a base, a document bracket, a paper detection device, an atomizing spraying device, a page turning device, a feed liquid pool, a hydrosolvent deacidification liquid defined amount control device and hydrosolvent deacidification liquid delivery pipelines, wherein the document bracket is arranged on the base, the paper detection device and the atomizing spraying device are arranged on the document bracket and located on the two sides of the document bracket respectively, and the page turning device is arranged in the middle of the document bracket; the hydrosolvent deacidification liquid defined amount control device is arranged between the atomizing spraying device and the feed liquid pool, the hydrosolvent deacidification liquid defined amount control device is connected with the atomizing spraying device and the feed liquid pool through the hydrosolvent deacidification liquid delivery pipelines respectively, the paper detection device, the hydrosolvent deacidification liquid defined amount control device, the atomizing spraying device and the automatic page turning device are all electrically connected with the controller, and a paper pH detector is arranged on the paper detection device. In this way, uniform deacidification of the whole paper document is achieved, alkali stock is uniform, and deformation and damage of the document are avoided.