As the investigation deepened, it is necessary to detect the hydrogen concentration with large quantities of points, in the field of nuclear power station, aerocraft engine, gaseous fuel, et al, but the existing optical fiber hydrogen sensing systems are able to measure only one point at a time. A Wavelength Division Multiplexed(WDM) optical fiber hydrogen sensing system was proposed for the detection of multi-point hydrogen. The topology, principle and advantage of WDM optical fiber hydrogen sensing system were expatiated, and the technical feasibility of the novel system was introduced in detail.According to the analysis, a WDM optical fiber hydrogen sensing system was assembled with four measuring channels using the components well developed in the telecommunication industry, and an additional scheme was also developed for the hydrogen experiment. The results show that the novel optical fiber hydrogen sensing system is able to measure multi-point hydrogen simultaneously, and different measuring channels do not interfere with one another by measuring spectral evolvement and power of the optical signal. The performance test shows that good stability(less than ±1% in an hour) and small error(less than ±2%) are achieved within the measuring range from 0 to 4%. The research results will provide a valuable reference for the optical fiber hydrogen sensing system to measure the hydrogen concentration with large quantities of points.