Hydrogen is a kind of ideal clean energy sources. With low energy consumption, environmental protection and other advantages, biological hydrogen production technology become the hotspot of current study home and abroad. The distribution energy technology for producing hydrogen can get hydrogen when deal with waste water. For finding out the industralized feasibility of continuous H2 bio-production,the ability of H2-production via facultative anaerobe,optimum hydraulic retention time(HRT) and optimum organic loading rate(OLR) were aslo studied. With a temperature of (35±1)°C，HRT of 8 h，the CSTR inoculated with activated sludge ,and the progression is increasing organic loading rate gradually. Six OLRs were examined, ranging from 2 to 12 g COD/L.d, with the mass of molasses ranging from 1.3 to 10 g COD/L. While COD was up to 4g/L(OLR 12kg/(m3•d)), all molasses was utilized and the H2 yield was not significantly influenced by OLR. At the intermediate COD of 6g/l (OLR 18kg/(m3•d)), the H2 yield was maximized at about 30 L/d H2 (mol molasses. Conv.), which was 17.9% and 55.9% higher than those of OLR 6 kg/(m3.d) and OLR 12 kg/(m3.d),respectively. When the influent COD concentration raised to 12g/L(OLR 30kg/(m3•d)), the reactor were overloaded, the hydrogen yield decreased drastically，hydrogen evolution rate decreased to zero. Exceeding OLR would arouse great change of internal environment parameters, such as pH, ALK(aikalinity), ORP(oxidation-reduction potential) in CSTR, and the microbial community structure would change while the metabolism of microorganism was inhibited badly.