Abstract: The method of orthogonal rotation combination test with four factors and five levels was applied to study the principle of the influence of parameters of extrusion system upon research indexes at the laboratory. These parameters include the temperature of the barrel, the diameter of the die nozzle, the moisture of corn germ and the speed of the screw. These parameters include the ratio of the residual oil, shearing strength and density of the extrudate. The optimum parameters of extrusion system are as follows: diameter of die nozzle with 9 mm , extrusion temperature 93℃, moisture of material 13.3%, speed of screw 238 r/min. The optimum value of the ratio of the residual oil is 0.40%. The time of solvent oil extraction will be reduced 50% compared with that of traditional rolling and pre-press pretreatment process. The capacity of solvent extraction of original extraction equipment will rise to 60%～120% if the parameters of corn germ extrusion system are appropriate.