Abstract: Irrigation methods play an important role in plant growth and development. Effects of irrigation methods on alfalfa growth was studied in order to explore the irrigation methods with high water use efficiency and provide a reference basis for water- saving irrigation in plants. The material used in the study was Medicago Sativa cv Xinmu No.4. The response of alfalfa growth was researched by setting different irrigation methods: drip, sprinkler and flood in the field of alfalfa. The leaf area, leaf relative water content, chlorophyll and other morphological and physiological indexes of alfalfa were measured in full bloom stage. The morphology and physiology of alfalfa were affected by different irrigation methods. The highest chlorophyll content and the lowest proline and malondialdehyde (MDA) content showed that the alfalfa was less damaged under drip irrigation; the cell membrane permeability, soluble sugar content, proline content and MAD content were all the highest under sprinkler irrigation, which was proved to be a relatively huge damage to the growth of alfalfa; the leaf area was the largest and the cell membrane permeability, chlorophyll content and soluble sugar content were the lowest under flood irrigation. Based on the comprehensive evaluation, considering high efficiency and water saving, drip irrigation was the best irrigation method for alfalfa growth and flood irrigation took the second place.