Water level is an important factor affecting the growth, development and reproduction of wetland plants. To clarify the effects of different water levels on the physiological characteristics of Carex cinerascens, the indoor pot method is used to set up three types of water environment: rising, falling and stable. Seven test treatments, including 8 cm (0.2 cm/d), 16 cm (0.4 cm/d), 24 cm (0.6 cm/d), 32 cm (0.8 cm/d), 40 cm (1.0 cm/d), 48 cm (1.2 cm/d), and 56 cm (1.4 cm/d) were set for each types of water environment, taking 0 cm water level as a control, the test time lasted 40 days. The indexes of antioxidant enzyme activity, osmotic adjustment substance content, malondialdehyde content and superoxide anion production rate of C. cinerascens under different water levels were analyzed. The results showed that 1) in the stable water level, the superoxide anion production rate, osmotic adjustment substance and antioxidant enzyme activity were significantly different from the control group at 8 cm and 16 cm flooding depth. Under 48 cm and 56 cm flooding conditions, antioxidant enzyme activity and osmotic adjustment substances increased first and then decreased, and malondialdehyde and superoxide anion production rates continued to increase. 2) Under the condition of risen water level, at a vibration intensity of 0.2 cm/d and 0.4 cm/d, the malondialdehyde content and superoxide anion production rate did not change significantly after 20-30 d. The 1.0 cm/d was the physiological regulation tolerance limit of C. cinerascens. When the processing intensity was greater than 1.0 cm/d, the physiological indexes and the processing intensity were less than 1.0 cm/d, and the change was obvious. 3) Under the condition of falling water level, it was affected by the initial water level. The malondialdehyde content showed a high-low-high trend at a processing intensity of 1.2 cm/d and 1.4 cm/d. The remaining test indicators showed a trend of increasing first and then decreasing, and with the increase of processing intensity, the difference in indicator changes continued to increase, and the time node from rising to the falling was continuous to delay. It could be seen that the flooded environment would destroy the homeostasis in the cells of C. cinerascens. Compared with the stable water level, the anti-oxidation and osmotic adjustment system of C. cinerascens could adapt to the water level changing environment faster, and the short-term, low-intensity water level change could promote physiological metabolism of C. cinerascens to a certain extent.