In view of the ecological function of Minjiang river basin,the paper utilized the analytic hierarchy process of multinorm to built three dimensional evaluation index about society development, economy development and ecology protection. It built the scientific and rational water allocation quantization mode in Minjiang river basin by taking administration zone of the basin as allocation target. The result shows that water allocation not only accords to society and economy index about water consumption and total economy, but also accords to ecological protection to carried out appropriate compensation,which can make the water allocation model more scientific , rational and acceptable to all parties and make the utilization of water resources of the basin more sustainable.