Corn grits were treated with 0.2% sulphurous acid solution. The purpose of this treatment is to protect pure bacteria (yeast, Lactobacillus) from fermentation. Based on the single factor test, the fermentation technique of instant corn noodle was optimized by orthogonal design. The optimum technological parameters were obtained as follows: 0.2% yeast, plus 0.1% lactobacillus bulgaricus, with fermentation time 78 hours, fermentation particle size 8 mm, and fermentation temperature 30 ℃. The product of fermentation was optimized as follows: 3.5% pregelatinized starch with 0.30% sodium hexametaphosphate, 1.0% xanthan gum, and 3% sunflower seed edible oil. The fermentation had the best comprehensive effect on the instant corn noodle with the broken strip rate of 4.5% and cooking loss rate of 4.5%. Through the mechanical hot extrusion of fermented dough, the broken rate of vermicelli was the lowest, which was 4.3%, and the sensory quality score reached 96.6%. The room temperature storage period of vacuum packaging is 14 days, and the cold storage period is 60 days.