Objective: The effects of lotus leaf coarse powder and lotus leaf superfine powder on the physical and chemical indexes of flour and its application in crisp biscuits were studied in this paper, and explored the suitable amount of lotus leaf coarse powder and lotus leaf superfine powder added in crisp biscuits. Methods: Farinograph, extensograph, wet gluten tester, and falling number tester were used to determine the effects of lotus leaf powder on the physical and chemical indexes of flour. The hardness of the dough and the shear force of the crisp biscuit were measured by the texture analyzer, and the sensory quality of the crisp biscuit was evaluated by the sensory method. The total number of bacteria in the raw material and crisp biscuits was determined by the method of total colony determination. Results: Adding 0%~15% lotus leaf coarse powder and lotus leaf superfine powder to the flour, the water absorption rate, falling number and hardness of the dough were increased, the stability time of the flour, the stretching energy of the dough and the wet gluten content were reduced, the crispness and sensory score of the crisp biscuit increased first and then decreased. When the addition amount of lotus leaf coarse powder was 6% and the addition amount of lotus leaf superfine powder was 9%, the crispness and sensory score of the crisp biscuit were the largest, compared with the blank, the sensory scores of the crispy biscuits were increased by 9.81% and 18.33% respectively, and the addition of lotus leaf superfine powder was 3% higher than that of lotus leaf coarse powder. Compared with the blank, the total number of bacteria in the crisp biscuit with 15% lotus leaf coarse powder decreased by 41.18%, and the total number of bacteria with 15% lotus leaf superfine powder decreased by 62.94%. Conclusion: The lotus leaf coarse powder and lotus leaf superfine powder could increase the nutritional value and sensory quality of crispy biscuits, and have the effects of inhibiting the bacterial growth of crispy biscuit. Compared with lotus leaf coarse powder, the effects of lotus leaf superfine powder that improved the quality of crispy biscuit and inhibited bacterial growth are better than lotus leaf coarse powder, and the lotus leaf superfine powder has more application value in crisp biscuits.