The invention provides a high-speed imaging device, a high-speed thermal printer and a printing method. The high-speed imaging device comprises a plurality of thermal sensitive modules, a plurality of rubber roller modules and a paper feeding driving device, and the thermal sensitive modules and the rubber roller modules are located on the two sides of a paper feeding channel; the thermosensitive module comprises a thermosensitive support and thermosensitive pieces, the thermosensitive pieces are arranged on the thermosensitive support, printing head arrays are arranged on the thermosensitive pieces, the multiple printing head arrays are overlapped along the paper feeding channel, the paper feeding driving device drives the rubber rollers to rotate synchronously, and one thermosensitive piece is opposite to one rubber roller. The at least two thermosensitive sheets are arranged on the same side of the paper feeding channel, and the imaging areas of the printing head arrays on the thermosensitive sheets are overlapped, so that the multiple thermosensitive sheets can image the same side of the printing medium for multiple times, even if the printing speed and the paper feeding speed are improved, the
imaging quality such as concentration and definition can be met, and the printing efficiency is improved. And the purpose of high-speed printing is achieved, and double-color or multi-
color printing can be achieved through the arrangement of the multiple thermosensitive pieces.