Studying the change characteristics of high-standard terrace ecological service function in loess region, discussing influence trend and potential of the project of changing mountain slop into terrace on functional value of high-standard terrace ecological service, can provide a theoretical basis for exploring the model of low input, high efficiency and sustainable agricultural development in loess hilly region. The study defined the ecological service function of high-standard terrace with opportunity cost method and shadow engineering method in Zhuanglang county. On the basis of soil fertility maintenance function, soil and water conservation function, and soil moisture conservation function, this paper built the model of material quality and value of ecological service function, and assessed ecological service function and value of high-standard terrace. The results showed:firstly, each hectare of high-standard terrace annually provided the total mass and value of ecological service for human beings respectively about 119 667.00 kg and 114 046.53 yuan, the value of ecological function was considerable. Secondly, soil erosion amount of sloping farmland and high-standard terrace was respectively 82.76 t/(hm²·a) and 0.05 t/(hm²·a), the amount of soil and water conservation of high-standard terrace was 82.71 t/(hm²·a), and the transformation of sloping farmland into high-standard terrace had a significant impact on the value of ecological service function. Thirdly, the value of soil and water conservation function of high-standard terrace unit area was 3 831.67 yuan/(hm²·a), far below the value of soil fertility maintenance function which was 88 869.52 yuan/(hm²·a) and the value of soil moisture conservation function which was 24 239.20 yuan/(hm²·a). There is still a lot of room for improvement and appreciation potential in the function of soil and water conservation in high-standard terrace, adjusting the industrial structure of terrace, selecting appropriate operation and development mode, improving the yield per unit area, and giving full play to the function of high-standard terrace. The construction of high-standard terrace has important features of production, ecology and living functions in the process of national economic development. The study provides a comprehensive evaluation method for the ecological function value accounting of high-standard terrace, and the results are helpful to improve the value accounting method of ecological function, maximize its ecological benefits, also excavate the potential ecological function and value, so as to realize the sustainable development of high-standard terrace ecosystem.