The application of metamaterial sensors is a hot topic in the field of material measurement. However, the resonant absorption modes are difficult to be eliminated due to many metamaterial sensors containing metal arrays. In measurements of the clothing fabrics, absorption rate requires a smooth spectrum in a wide frequency range. Here, an all-dielectric metamaterial is proposed and measured, and a smooth absorption spectrum is achieved (average absorptivity of 25.2%). When this metamaterial is covered by a fabric sample (Polyester), the measured average absorptivity is 41.5%. When the thickness of the fabric sample Polyester is set to be 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm, the measured average absorptivity of the Polyester is: 41.5%, 48.3, 57.6, 62.1, respectively. Moreover, four fabric samples are measured and the achieved absorptivity is: 41.5%, 25.1%, 34.3%, and 56.6%, respectively. The simulated results are close to the measurement results. This all-dielectric metamaterial demonstrates the feasibility of clothing fabric measurement.