The invention relates to a metamaterial radome with a smoothing function and an antenna. The metamaterial radome comprises at least one metamaterial piece layer, each metamaterial piece layer comprises a substrate and a plurality of artificial microstructures of the same size arranged on the substrate in an array mode, and each artificial microstructure is of a circular ring structure. Due to the fact that the artificial microstructures of specific shapes are adhered to the substrates, needed electromagnetic response is obtained, and the radome based on a metamaterial has the certain smoothing function. The relative dielectric constant, the refractive index, impedance and the smoothing frequency band of the material are changed through changing of the shape and the size of the artificial metal microstructures, and limit for the thickness of the material and a dielectric constant when a traditional radome is designed is reduced. As for a double-frequency-point antenna or a multi-frequency-point antenna, mutual interference among multiple frequency points can be reduced by the adoption of the radome, and normal operation of the frequency points is guaranteed. In addition, the radome is quite thin, the overall size of the antenna is reduced, the weight of the antenna is reduced, and meanwhile installation and maintenance are facilitated.