In this paper, a novel converter based on metasurface is proposed, which can realize the conversion between linear polarization and circular polarization. The converter is elliptical in structure and has many excellent features such as ultra-wideband, compact and high efficiency. Through the simulation and processing experiments of the converter, it is found that the working frequency of the converter is 10.3GHz ~ 25.2GHz, and the frequency band width is about 85%. In this frequency band, the frequency band of circularly polarized wave is no more than 3dB. The experimental results show that when the incident angle is ±50°, the linear polarization and circular polarization conversion characteristics are good at 11GHz ~ 22GHz. This converter is compact in structure and can convert linear polarization to circular polarization in a wide frequency band, which has a wide application prospect.