Abstract: s: Rational use of water resources directly affects the productivity of land resources, and the development and utilization of land resources also affects the degree of efficiency of water use. With the worsening situation of agricultural water and the increasing demand of agricultural water, the adjustment and optimization of region planting structure become one of the most important and effective measures to alleviate the conflict between region agricultural development and water shortages. The necessity of adjusting and optimizing region planting structure is more urgent especially in arid and semi-arid regions. The Loess Plateau region is an important part of the Guanzhong irrigated agricultural area. In recent years, with the rapid development of the local economy and society, domestic water, industrial water and ecological water increased rapidly. Crop irrigation water is significantly affected. Agricultural development and the contradiction between supply and demand of water resources has become increasingly prominent. This paper established the planting structure multi-objective fuzzy optimization model, which aim to make full use of water resources, ensuring the food security, increase crop output and improve the return on investment and so on, and measured the optimization programs at different input levels and food security levels, and used the data envelopment analysis (DEA) model to evaluate input-output efficiency values of the optimization programs. High capital investment can improve the efficiency of input and output, high capital investment is better than that of low capital investment. With increased investment in water and soil resources, more money to invest in local advantages crops, planting each benefit significantly improve the efficiency per unit of land is higher than the low level of capital investment, and return on capital investment also increased. The results showed that the type of high capital investment and food supply program is the best program for planting structure optimization in the Loess Tableland Area. Through analyzing different optimization scheme and comparing with situation in planting structure, to the Loess Tableland Area is put forward the following suggestions. First, the area sown in the study area should be increased by 18.8% in 2015 (increased to 52.16×104 hm2). Second, increasing economic and forage crop planting proportion, food crops, cash crops and forage crop proportion of ternary planting structure adjustment for 64:31:5. Third, keeping the sustained increase in agricultural investment and increasing by 37.8% based on the investment in 2010 to achieve the objective of maximizing the overall efficiency of region