To solve the problem of plant dieback over winter, four kinds of woody plants have been applied to constructed wetland and a series of physiological and biochemical indicators have been measured to analyze the adaptability and decontamination capability of the plants. The results showed that: (1) The diurnal variation of the net photosynthetic rate of oleander, gardenia and privet was of a "Twin Peaks" type, while the hibiscus was "unimodal" type; the diurnal variation of the leaves stomatal conductance of hibiscus was of "unimodal" type while the other three varieties showed no obvious trend. The highest peak time of the four plants was inconsistent and the diurnal variation of CO₂ concentration in the plant cells was contrary to the diurnal variation of the net photosynthetic rate. The diurnal variation of the transpiration rate of the four woody plants was of "unimodal" type with the peak time appearing at 11:00-13:00. (2) The Chlorophyll content of privet is low compared to that of the other three kinds of plants, which are all similarly high. The hibiscus and gardenia had the highest accumulation of malondialdehyde while the ligustrumlucidum contained the lowest accumulation. The nerium oleander had the highest nitrogen and phosphorus content and the hibiscus syriacus had the lowest, related to the biomass. The total phosphorus accumulation of the gardenia was low. The urease activity of the matrix was higher in the oleander and hibiscus than in the gardenia and privet and the activity of matrix phosphatase was approaching in four plants. (3) The change of external morphology and internal structure. External morphology is introduced into wetlands on four kinds of woody plants growing out of the aquatic root system of significantly increased white fibrous root, root number and significantly more land soil cultivation conditions, suggesting that the four kinds of plant root system can adapt to an artificial wetland environment. On the internal structure of four kinds of bacon with a hydroponic plant soil root system have bigger differences in the internal structure. The soil bacon system organization is very dense, but after the introduction of wetland plants, root systems have developed aerenchyma. (4) The research into the decontamination effect of four woody plants in constructed wetland showed that over the whole test, TN removal rate was on average 40.2%. TP removal rate was on average up to 80.8%. The lower average removal rate of COD_Cr was 15.4%, the average removal rate of NH₄⁺-N was 61.8%, and the change between each month usually appears as a change of seasonal temperature change rule. The higher the temperature, the greater the processing efficiency and at low temperatures the treatment effect is poor. Therefore, this research into the four kinds of woody plants can be well applied to the undercurrent of artificial wetland systems.