A warp-knitted integrated plush fabric and preparation method thereof are provided. The plush fabric includes a first plush layer, a second plush layer, and a connecting layer; wherein the first plush layer includes a front guide bar underlap layer formed by processing the front guide bar underlaps; the connecting layer, from the first plush layer to the second plush layer, successively includes a middle guide bar underlap layer, a back guide bar underlap layer, a middle guide bar loop layer, and a front guide bar loop layer, each layer being formed by interknitting the corresponding middle guide bar underlaps, back guide bar underlaps, middle guide bar loops, and front guide bar loops successively; the second plush layer includes a back guide bar loop layer, a back guide bar underlap layer, or a combination of both. The preparation method includes the steps of yarn warping, on-machine knitting, and dyeing and finishing.