Biomass energy was one kind of substituent energy due to the decrease of fossil fuel and its pollution. The effects of factors on biomass pyrolysis were investigated using wood sawdust and straw as biomass materials by a self-manufactured fluidized bed reactor. Results showed that the highest bio-oil yield was obtained at 500℃ with pine wood sawdust as biomass material. The effect of pyrolysis temperature on yield of bio-oil was big. When pyrolysis temperature was increased, the yield of pyrolysis gas as well as its heating value was increased, and the yield of char was decreased. Pyrolysis gas component varied with reaction time, the rate of flammable gas in pyrolysis gas was the highest at about 10 min.