The orthogonal experiment was carried out on the pyrolysis temperature, the heating rate and the residence time using the mass yield, the energy yield and the high heating value as the evaluation index by which the optimum processing conditions of torrefaction of corn stalk pellets were determined. The results showed that the optimal process conditions are 290℃ of pyrolysis temperature, 7.0℃/min of the heating rate, 45 min of the residence time, and the higher heating value and the energy yield are 20.32 MJ/kg and 75.37%, respectively. The analysis of product quality including the water content, equilibrium moisture content, water absorption, durability and drop strength of the products showed that torrefaction corn straw pellets can be stored and transported advantageously.