Tetrahedral amorphous carbon (ta-C) films under different substrate negative bias are prepared by a home developed filtered cathodic vacuum arc (FCVA) technology with double bend shape. The film thickness is measured by a combined spectrophotometry and spectroscopic ellipsometry (SE) approach; the chemical bonds including sp2C and sp3C are gained by the fitted ellipsometry method. Furthermore, the accuracy of ellipsometry results is evaluated by comparing with those of X-ray photoelectron spectroscopy (XPS) and Raman spectra. The results indicate that the minimum thickness of ta-C film of 33.9 nm is obtained when the bias voltage is -100 V; with the increase of bias voltage, the optical gaps and the content of sp3C atomic bond decrease, while the sp2C content increases correspondingly. By comparison with the results of XPS and Raman spectra, it is found that when the optical constants of sp2C model are represented by the glassy carbon and the fitting wavelength ranges are chosen from 250 to 1700 nm, the best fitting result of atomic bonds of ta-C films can be deduced by the ellipsometry method. Therefore, it could be said that the elliposometry method is a quite promising method to characterize the atomic bonds of ta-C films including sp2C and sp3C, as a new nondestructive, fast, quantitative and easy way.