Late blight is an epidemic fungal disease spread by air currents. Late blight may occur when the temperature is above 10°C and the air humidity is above 85 for 24 consecutive hours. The more vigorous the growth, luxuriant branches and leaves, and closed fields, the more conducive to the occurrence and prevalence of late blight. Key points for prevention and control: ① Select disease-resistant varieties suitable for local planting. ② Agricultural measures: adjust the sowing period to avoid the occurrence period of late blight. Adjust the row spacing between plants and change the row spacing from small row spacing to large row spacing. Reduce the spread of pathogens by intercropping with crops such as corn. Thicken the soil layer. Crop rotation can reduce the damage caused by soil diseases by rotating crops with non-solanaceous crops for more than 3 years. ③Pharmaceutical prevention and control, the pesticides should be used in rotation to prevent the development of drug resistance. At present, commonly used pharmaceuticals in production include: Yinfali, Jinredomir, Anke, Amicida, Yikuaijing, An Taisheng and other protective and therapeutic agents. In order to improve the efficacy and enhance the adsorption force of the medicinal solution on the leaves, synergists can be added to the medicinal solution.