We propose a parallel generation method for multi-band linear frequency modulated (LFM) signals based on an extensible optical frequency operation module (OFOM). By replicating the second-stage spectral manipulation architecture, we achieve the parallel generation of multiple radar signals. Additionally, we discuss the optimization method for the output signal-to-clutter ratio (SCR) of OFOM. Compared to traditional methods for parallel multi-band signal generation, the proposed method not only simultaneously generates ultra-wideband dual-band signals but also allows for independent tuning of the generated signal parameters, while maintaining a simple and reliable system structure. In our experiments, we use this method to generate dual-band signals ranging from the very high frequency (VHF) band to the X-band, with bandwidths adjustable from 2.4 MHz to 6 GHz, and capable of producing large bandwidth signals of 1.2 GHz at low central frequencies. This technology holds potential applications in future radar systems, significantly enhancing system performance and expanding functionalities.