In recent years, the clubroot disease of cabbage has been severely developed in our city, and there has been a tendency to expand and spread. The primary area is mainly concentrated in the two districts of the city such as Changliu, Jiangnan, Jinchang, etc. Now it has expanded to Tongsong County's Guosong and Xijiang Townships. Cabbage clubroot disease mainly harms crucifer crops, and the onset of plots seriously affects the quality and yield of vegetables and even eliminates them. The causes of the clubroot disease in cabbage and its control methods are described below for reference by farmers. Symptoms: Seedlings or adults of Chinese cabbage vegetables such as Chinese cabbage, Chinese cabbage, Chinese cabbage, and Chinese cabbage can be killed. The pale leaf color of the diseased plants withered and drooped, especially after sunny noon. The swelling of the roots of the diseased plants was tumor-like. Its shape and size were greatly affected by the growth site. The tumors on the main root were close to the upper part, spherical or nearly spherical, the surface was uneven, rough, and the epidermis was cracked or not cracked; the tumors on the root were measured. Mostly cylindrical, finger-like; the number of tumors on the fibrous roots, up to more than 20, and string together. In the later stage of disease, the diseased part is easily infiltrated by soft rot bacteria, causing tissue rot or collapse, and the odor causes the whole plant to die. Pathogen: Plasmodiophora brassicae Woron. It is known as Plasmodiophora brassicae and belongs to Myxomycetes. Dormant sporangia formed in host cells, spherical or oval, thin, colorless, unit cell, size 4.6 ~ 6.0l.6 ~ 4.6 microns, germinated zoospore. Zoospore-shaped pear or spherical, 2.5-3.5 μm in diameter, with two flagellums of varying lengths in the front, which can swim in water and become deformed after standing, from the root hairs of cabbage vegetables invade host cells. A series of evolution and expansion, from the root cortex to the formation layer, stimulate the host parenchyma cells to divide, expand, cause the root system to form tumors, and finally the bacteria forms a large number of dormant sporangia in the host cells. After the roots rot, the dormant sporangia enter the soil. Winter in the middle. Transmission route and onset conditions: The pathogens live in the soil with a dormant sporangia or adhere to the seeds, and can survive in the soil for 10-15 years. The sporangia are transmitted through rainwater, irrigation water, pests, and agricultural operations. The spores invade the host by germination, and the roots of the spore sac are tumour-bearing for about 10 days. Bacteria can be developed in 9 ~ 300C, suitable temperature 230C, suitable relative humidity 50 to 98%. Soil moisture content below 45% died of pathogens, suitable pH 6.2, less than the incidence of pH 7.2. General low-lying and water changes into dry fields or after CaO deficiency. Control methods: (1) More than 3 years of rotation should be adopted to avoid planting cabbage vegetables in low-lying water or rice fields in vegetable fields or acid soils. (2) Seedlings transplanted with Chinese cabbage are planted with disease-free soil or formalin or pentachloronitrogen-preserved seedbed before sowing. (3) To improve the soil in the planting field, combine the soil preparation with 100-150 kg of slaked lime per mu in the acid soil, and add organic fertilizer. (4) Strengthen the cultivation and management, eliminate the water in the field in time, seriously remove the diseased plants and carry them out of the field to burn them. Disperse lime around the diseased points to prevent the spread of germs. (5) When necessary, irrigate the roots with 500% suspension of 40% pentachloronitrobenzene powder, 0.4-0.5 liters per plant, or 40% perchloric nitrobenzene, 4-30 kg per mu, and 40-50 kg fine soil. After planting a hole in the ditch and planting cabbage vegetables.