Taking Yiwu county and Qinghe county in high altitude area of northern Xinjiang for example, based on the calculation of reference crop evapotranspiration with the Penman-Monteith equation,the paper got the irrigation system under the three irrigation ways such as ground irrigation, sprinkler irrigation, drip irrigation in different level years in alfalfa grown period. The results show that in the same level year, the minimum value of irrigation quota and the maximum number of irrigation frequency are drip irrigation. Under the condition of the same level year and the same irrigation way,the irrigation frequency and irrigation quota in Yiwu are more than that in Qinghe. In each level year, the irrigation times in July and August account for a significant proportion of the times during the whole growth period.The results can provide the basis for improving the irrigation and management level of alfalfa in Yiwu and Qinghe and provide the reference for the formulation of irrigation system of alfalfa in similar climate areas.