A face handwriting input system based on image acquisition comprises an input panel, an input device, a processing unit and a server platform for storing handwriting input content. Coordinate points are arranged on the input panel to form an input coordinate system, the input device comprises a writing surface, a pressure sensor and an image collector, the writing surface is in contact with the input panel during handwriting operation, and positioning points on the outer edge of the writing surface are contained in the view field of the image collector. The processing unit receives image information of the image collector, calculates handwriting input content and sends the handwriting input content to the server platform. The systrm has the advantages of high handwriting restoration degree, wide writing scene and the like.