Abstract: In order to solve the problem of continuous culture of photosynthetic bacteria(PSB) for scaled hydrogen production, the authors not only synthetically measure the growth curve of PSB, but also calculate PSB doubling time according to different initialization values of OD660 based on standard curve. Also, according to basic demand and engineering practice of PSB for continuous hydrogen production, a set of partially recycled experimental equipment was designed. The experimental results show that the following conditions are in line with the requirements of photosynthetic bacteria hydrogen production: PSB continuous culture and the exit PSB concentration equals to 0.38～0.74, initialization values of OD660: 0.273, anaerobic, temperature: (30±1)℃, ray intensity: 1200Lux, continuous irradiation and culture cycle: 38 h.