In this paper, a depth-graded C/W multilayer mirror with broad grazing incident angular range, consisting of three multilayer stacks, each of which has different period thickness d and the layer pair number, was designed and fabricated by direct current (DC) magnetron sputtering. For calculating the definite performance of such a mirror, the saturation effects of the interfacial imperfection, such as interface roughness and diffusion, were emerged. The reflectivity of the mirror was measured by the X-ray diffraction (XRD) instrument at Cu Kα radiation (λ = 0.154 nm), the measured reflectivity was about 30% in a broad grazing incident angular range (0.55---0.85 deg.). By the fitting data, the thickness of each layer is almost same as the one designed and the roughness in the multilayer is about 0.85 nm, which is larger than the prospective value of 0.5 nm.