Taking the garlicwatermelon allelopathy associated cultivation model as the research object, we set up three treatments of watermelon monocropping, garlic seedling stage accompanying watermelon, garlic full growth stage accompanying watermelon, and investigated the incidence of watermelon fusarium wilt, watermelon leaf antioxidant enzyme activities and osmotic adjustment substance contents, as well as rhizosphere soil enzyme activity and microbial quantity, to explore the influence of garlic accompanying on the enzymatic antioxidant system of watermelon and soil characteristics. The results showed that: (1) in the garlicassociated cultivation system, the incidence of watermelon fusarium wilt was significantly lower than that of the monoculture control, and the associated treatment effect during the whole growth period was better. (2) The garlicassociated cultivation of watermelon leaf antioxidant enzymes (superoxide dismutase, superoxide dismutase, etc.) activities of peroxidase and catalase were significantly increased compared with the single control, and the increase in the associated treatments during the whole growth period was greater. (3) The soluble sugar and soluble protein contents in leaves of the garlicassociated cultivated watermelon were significantly increased than the single control, while its proline content was significantly reduced, and the accompanying treatments changed more throughout the growth period. (4) The number of fungi and Fusarium oxysporum in the rhizosphere soil of the garlicassociated watermelon was significantly reduced compared to the single control, while the number of bacteria and actinomycetes significantly increased. At the same time, the activities of polyphenol oxidase, peroxidase and urease in the rhizosphere soil of watermelon increased compared with the control, while the activity of invertase decreased significantly. It can be seen that garlicassociated cultivation significantly inhibited the incidence of watermelon fusarium wilt, enhanced plant leaf antioxidant enzyme activities, increased plant leaf osmotic adjustment substance contents, and effectively improved rhizosphere soil colony balance and soil enzyme activities, thereby increasing watermelon resistance and rhizosphere soil quality, effectively breaking the watermelon continuous cropping barriers.