We propose a scheme of optical frequency comb (OFC) generation based on cascaded Mach–Zehnder modulator (MZM) and electroabsorption modulator (EAM) with Gaussian-shaped pulse signal. In the proposed scheme, the MZM and the nonzero-chirp EAM are driven by a periodic Gaussian-shaped pulse signal that is controlled with binary sequences, and then an OFC is output from EAM. The theoretical model of the OFC generation is developed by improving the theory of electroabsorption modulation. The performance of OFC is investigated. The results show that the frequency spacing of the OFC can be tuned in the range of 1 to 10 GHz, the number of effective comb-lines is 35, and the power variation of comb-lines is 2.14 dB.