Abstract: Protected horticultural technology in China has being developed into a system with more and more completely systematic characteristics and has being become the most active element in the development of the industry. As a fundamental critical study for revealing the characteristics of protected horticultural technology system, improving the discipline construction and instructing the scientific research and technique extension, technology classification was in need of the methodology and practice study to guide the comprehensive coordination and sustainable development of protected agricultural engineering technology based on understanding the different contradiction and special motion of different technical objects. Based on the generalized conception and generalized elements of protected agricultural engineering technology, 4 level line classification method was put forward, which identified the attributes of technical chain, technology link, technology function and technology measures of the protected agricultural engineering technology respectively, through the analysis of the content and features of protected agricultural engineering technology, and existing technical classification methods, by following the systematic rules of hierarchy, stability, openness, and reality. The facility horticultural technology was taken as an example to validate classification method. The results showed that the method could comparatively reflect the engineering technology panorama of protected agricultural and reveal the structure and functional characteristics of the technology system. This research provides reference and theoretical support for the discipline development, technological innovation as well as industrial upgrading.