Diallyl disulfide （DADS） is a biologically active organic sulfide produced by the decomposition of allicin， which has a strong effect on inhibiting plant stress. The Chinese cabbage variety ‘Golden Kirin’ was used to study the effect of DADS on mitigating the autotoxicity of Chinese cabbage. 6 groups of treatments including CK1（1/2 Hoagland nutrient solution）， CK2（continuous cropping solution）， D1 （1 μmol/L DADS + continuous cropping solution）， D5 （5 μmol/L DADS + continuous cropping solution）， D10 （10 μmol/L DADS + continuous cropping solution）， D15 （15 μmol/L DADS + continuous cropping solution） were set up using hydroponic experiment， with 12 tissue culture bottles in each treatment and 4 seedlings cultured in each bottle. The effects of different concentrations of DADS on the growth， physiological and biochemical trait of seedlings under the autotoxicity of Chinese cabbage were investigated. The results showed that the application of different concentrations of DADS had an effect on promoting the growth of seedlings under the autotoxicity of Chinese cabbage， with D5 having the best effect of mitigating. Compared with CK2， D5 treatment significantly increased the fresh weight of aboveground and underground parts of seedlings， and root activity of Chinese cabbage by 19.42% and 23.40%， and 45.29%. The length of total root and the number of root tip increased as well， which mitigated the damage of autotoxicity effect on root structure； meanwhile， the content of chlorophyll in leaves was increased， which promoted the photosynthesis in turn. The content of osmoregulatory substances in seedlings of Chinese cabbage significantly increased， with the activity of antioxidant enzyme SOD， POD， and CAT increasing by 30.75%， 27.44%， and 17.68%， and the content of MDA significantly decreasing by 20.58%. The results of histological staining showed that the accumulation of hydrogen peroxide anion and superoxide anion was significantly reduced by D5 treatment. It is indicated that exogenous application of diallyl disulfide （DADS） can effectively mitigate the autotoxicity of exudates from the roots of Chinese cabbage by reducing the oxidative stress and promoting the growth of root. The most significant mitigating effect was observed when 5 μmol/L DADS was applied. It will provide a new method to mitigate the obstacles of continuous cropping caused by the autotoxicity and lay the foundation for the rational use of diallyl disulfide （DADS）.