Using the variety "Chunbao Huang" of baby Chinese cabbage as material, the effects of different water and nitrogen treatments on the growth and physiological and biochemical indexes of cabbage were studied. The results showed that the cabbage under A1N2 treatment was the best in the morphological traits including number of outer leaves, number of leaflets, transverse stem, vertical diameter, biological yield and economic yield, and the values were 7.37, 39.73, 15.48 cm, 28.92 cm and 208.99 t/hm2 and 64.12 t/hm2, respectively. At the same time, the content of MDA in the leaves was 1.15 μmol/g, the root activity was the strongest, the activities of peroxidase (POD) and superoxide dismutase (SOD) were the highest, 269.8 μg/(g·h), 515 U/(g·min) and 418 U/g, respectively. The effects of the treatments on biological yield, economic yield, root activity, POD and SOD were in the order of A1N2> A2N2> A3N2> A1N1> A2N1> A3N1> A1N3> A2N3> A3N3