The present invention provides a liquid crystal display (LCD) module and a one-piece back plate thereof. The one-piece back plate of the LCD module comprises a plurality of first stepped portions, a plurality of second stepped portions and a plurality of engaging portions extending and being bent from the bottom thereof in sequence. An optical film assembly is supported and mounted by the first stepped portions, and a liquid crystal panel is supported and mounted by the second stepped portions. With the design of the one-piece back plate of the LCD module of the present invention, it is possible to omit the housing and the front frame, and the liquid crystal panel can be directly arranged on the one-piece back plate, so as to simplify and speed up the assembly process, and to further reduce the research cost, development cycle and production cost thereof.