Abstract: Extruding experiments were conducted in order to optimize theextruder performance, lower toxicity of flaxseed. SLG67-18.5 twin-screw extruder was used in the experiments. In the study the effects of temperature, moisture and screw speed and feeding speed on the removal rate of HCN in flaxseed wereinvestigated. The results were analyzed with orthogonal rotary regression method to establish the relationship between performance function and each parameter.Single factors and correlative effects on performance were also discussed based onthe regression model. Experimental results show that removal rate of HCN in flaxseed increased correspondingly with the increase of temperature, the increasedmoisture, and the improved screw speed. The effect of feeding speed on removal rate of HCN in flaxseed follows a parabola function law and middle value has better detoxification effects. An optimum range under 95% probability of removal rate of HCN more than 90% can be summarized for temperature, moisture and screw speed and feeding speed at 147～153℃, 13.8%～17.6%, 186～211 r/min and 61.7～74.0 kg/h, respectively by frequency analytical method. The study provides useful formation for detoxificationof flaxseed and the operation and adjustment of existing extruder.