Abstract: Currently China is implementing strategy of rural revitalization． In addition, it has put forward concept of New Engineering and New Agricultural Discipline construction in education reform． Therefore, development of agricultural engineering discipline has ushered in great opportunities and grand challenges． In order to better serve rural revitalization, expansion direction of agricultural engineering discipline was explored to seek innovation of discipline content with Chinese characteristics． Based on analysis of frontier progress of world agricultural engineering discipline, China's agricultural and rural development stage, characteristics and major needs of rural revitalization, it was considered that research frontier of world's agricultural engineering was biological system engineering, but China can't copy advanced model of foreign agricultural engineering disciplines． China needs to expand direction of agricultural engineering on basis of original secondary disciplines, including ecological agricultural engineering, physical agricultural engineering and biological system engineering, etc． Concept and connotation of ecological agricultural engineering was put forward． it was considered that ecological agricultural engineering was ecological development of agricultural engineering, it was an interdisciplinary subject of agricultural engineering and ecological engineering, and it could be regarded as a branch of agricultural engineering． It conformed to concept of interdisciplinary and integrated development of new engineering and new agricultural science． Under background of rural revitalization in China, it is also necessary to expand direction of ecological agricultural engineering, which is mainly manifested as follows: ecological civilization construction is an important part of rural revitalization, prominent resource and environment problems urgently need to develop ecological agricultural projects, ecological agricultural engineering is realizing way of rural revitalization and rural revitalization calls for ecological agricultural engineering． Suggestions for development of ecological agricultural engineering were proposed, which included giving play to systematic role of agricultural engineering in rural revitalization, highlighting field of rural construction projects in rural revitalization, giving full play to supporting role of agricultural engineering discipline in ecological agricultural engineering, and strengthening discipline research and personnel training of ecological agricultural engineering etc． Innovation and expansion of ecological agricultural engineering in agricultural engineering field met internal requirements of China's contemporary rural ecological revitalization, and it would play an important role in discipline construction of agricultural engineering, agricultural production practice, agricultural and rural modernization in China．