Diseases of watermelon mainly include damping-off, blight, blight, powdery mildew, and anthrax. Suffering from damping-off and blight, can use carbendazim and green hen No. 1 seed bed disinfection; with wilt, can use 15% of watermelon broth No. 1 300-350 times Irrigation. 0.5 kg each time, after 3-4 true leaves are planted, the control effect is better; powdery mildew and anthrax, chlorothalonil, thiophanate-methyl, and powder rust can be used for better control and alternate use. Insect pests of watermelon mainly include insects, aphids, ladybugs, root beetles, and red spiders. The control agents may be alternately controlled with avermectin, dichlorvos, and dichlorvos, and roots may be treated with trichlorfon. Promote the installation of insecticidal lamps and yellow traps for physical control. Root-knot nematodes mainly infect the plants at the seedling stage, causing great harm. Therefore, it is important to choose plots with no root knot nematodes. If nematodes are found after the colonization of seedlings, avermectin agents such as 1% aphid chrysanthemum 2000 times solution and 1.8% abadin 3000 times solution can be used for root irritation. Daejeon can use pesticides such as phoxim, merrol, thiocarbacarb, diazinon, and chlorpyrifos during soil preparation.