Abstract: The cooking extrusion conditions and formula of corn snack produced by BC45 co-rotating twin screw extruder were discussed in this paper. It is found that the corn snack with high quality can be produced on the following conditions: 160℃ of the die temperature, 150 r/min of screw rotation speed, 30 kg/h of feed rate and at the formula of 8% of water ,69.6% of corn powder,17.4% of rice powder, 4% of sugar and 1% of salt.