Oil shale screenings (d <= 10 mm), not used for the Fushun retort in the Fushun retorting plant of China, were crushed and sieved to different fractions of fine particles (in the range of 0-0.95 mm) which were pyrolysed in an experimental fluidized-bed reactor developed by the Institute of Comprehensive Utilization of Waste, Jilin Agricultural University. The optimum pyrolysis parameters of fine-particle oil shale were determined via orthogonal experiments, and one-factor experiment was performed to verify the results of the orthogonal experiments. The effects of oil shale particle size, feeding rate and reaction temperature on the yield of shale oil were analyzed. The results showed that the yield of shale oil reached 5.13% under the optimum experiment conditions, and the optimum combination was as follows: particle size of oil shale less than 0.47 mm; feeding rate 14 kg/h (residence time 11 min) and reactor temperature 450-500 degrees C. Experimental parameters of flash pyrolysis of oil shale fine particles will provide theoretical basis for utilizing shale screenings of retorting plant.