A large-size wafer entire nanoimprinting device and an imprinting method therefor. The device comprises an upper cavity (9) and a lower cavity (3), the lower cavity (3) being driven by a first raising and lowering mechanism (2) to move up and down to come into contact with or be separated from the upper cavity (9), an elastic mould (8) used for imprinting being arranged on a bottom portion of the upper cavity (9), a wafer-bearing platform (4) being horizontally arranged within the lower cavity (3), a bottom portion of the wafer-bearing platform (4) being provided with a second raising and lowering mechanism (1), an upper cavity air inlet (902) movably connected to a pressure pipe (13) being arranged on a cavity wall of the upper cavity (9), a lower cavity air inlet (301) movably connected to both a vacuum pipe (12) and the pressure pipe (13) being arranged on a cavity wall of the lower cavity (3), a wafer-bearing platform air inlet in communication with the vacuum pipe (12) being arranged on the wafer-bearing platform (4), the device also comprising an exposure light source (11). The nanoimprinting device and the imprinting method therefor implement large-size, uneven substrate and fragile substrate large-area micro/nanostructure high-efficiency and low-cost batch manufacturing, and provide an industrial-grade solution for large-size wafer-level large-area micro/nanostructure manufacturing.