In recent years, high temperature steam gasification (HTSG) is a new gasification technology which utilizes super-heated, high temperature steam as gasifying agent as well as partial heat carrier. A HTSG experimental platform for generating hydrogen-rich gas from biomass was proposed. The experimental platform included a high temperature steam generating system, a downdraft gasifier, a gas purification system, a sample gas collection system and an automatic control system. The gasification performance of the downdraft gasifier was evaluated by using pine wood shavings which considered the effects of reaction temperature. The steam temperature was controlled from 600℃ to 1000℃ during experiment. The results showed that combustible gas composition over volume fraction of 77% was obtained in these experiments. The volume fraction of H2 increased and CO and CH4 decreased as the reaction temperature increased. When steam temperature was (948±4)℃, the volume fraction of H2 reached (51.83±0.12)%, the lower heating value of produced gas was 9.81MJ/m3, composition ratio of H2/CO reached 2.17 and the gas produced by high temperature steam gasification can be stable to burn, thus the gasification performance was regarded as relatively perfect. High temperature steam gasification is an effective way by using biomass such as pine wood shavings for making hydrogen rich gas, and it has the huge development potential and application space. The results could provide guidance for gasifier and engineering design of the biomass gasification.