Abstract: Biological hydrogen production via photo-fermentation plays a key role in carbon reduction and circular economy. Spectral conversion has been recognized as an effective approach to enhance the efficient of biological hydrogen production via photo-fermentation by improving the photosynthetic efficiency. This study aimed to improve the photosynthetic rate and biohydrogen production by developing a dual-emission peak spectral converter to converter the high-energy light that inefficiently utilized by the photosynthetic bacterium HAU-M1, into two characteristic absorption peaks at 490 nm and 592 nm in the visible region, thereby achieving synergistic enhancement of effective light absorption. Dual-emission peak spectral converters were fabricated by mixing phosphors with emission peaks at 482 nm and 596 nm at five mass ratios (4∶1, 2∶1, 1∶1, 1∶2, and 1∶4). The transmittance and haze of the 5 dual-emission peak spectral converters were in ranges of 70.1%-81.4% and 80.0%-90.0%, respectively. The average optical power intensity loss and light intensity loss of the 5 dual-emission peak spectral converters were 13.0% and 14.5%, respectively. Amongst, the dual-emission peak spectral converter with a mixing ratio of 1∶4 gave the maximum optical power intensity loss and light intensity loss of 17.0% and 20.9%, while he dual-emission peak spectral converter with a mixing ratio of 4∶1 achieved the minimum optical power intensity loss of 10.0%. It was found that the mixing ratio of the phosphors with emission peaks at 482 nm and 596 nm did not affect the positions of the absorption and emission peaks of no matter at the liquid from or sold form that was fabricated into the spectral converters. The effects of these five spectral converters on bacterial dry weight, photosynthetic pigment contents (bacteriochlorophyll and carotenoids), photosynthetic rate, cumulative hydrogen production, hydrogen production rate, and light transmission characteristics were systematically investigated. The bacterial dry weight, bacterial chlorophyll content, carotenoid content, and photosynthetic rate of spectral converter with a mixing ratio of 1∶2 were increased by 33.5%, 35.2%, 33.1%, and 63.6%, respectively compared to control group. In contrast, the spectral converter with a mixing ratio of 2∶1 achieved the highest cumulative hydrogen production of 261.61 mL, which was 20.3% higher over the control group, followed by the 1∶1 experimental group with 248.78 mL, the 4∶1 experimental group with 240.53 mL, the 1∶2 experimental group with 238.74 mL, and the 1∶4 experimental group with 228.29 mL, representing increases of 14.3%, 10.6%, 10.0%, and 5.0%, respectively. Furthermore, the diffidence between bacterial dry weight and hydrogen production indicated the existence of competitive between Calvin Benson Bassham cycle and tricarboxylic acid cycle during the hydrogen production process. In addition, the dual-emission peak spectral converter could influence the transmission performance of light in the bacterial suspension by regulating the growth and pigment synthesis of photosynthetic bacteria, and the spectral converter with a mixing ratio of 2∶1 exhibited the highest light absorption capacity, which was align with its optimal hydrogen production performance. Moreover, the dual-emission peak spectral conversion strategy optimized the metabolic pathway by increasing the amount of efficient light that matches the absorption peaks of photosynthetic bacteria at 482 nm and 596 nm in visible light region, which provides a new approach for enhancing the biohydrogen production process via photo-fermentation.