In view of the problems of randomness, liveliness and diversity of traditional saddle shape, the work aims to propose and construct a research model of the traditional saddle shape and ergonomics to explore the rationality and amenity of the interface between saddle shape and people, and between saddle shape and horse, so as to promote the innovation and inheritance of traditional saddles. The traditional saddle of Hulun Buir was selected as the research object through field investigation, analysis and comparison, the shape composition of the saddle was analyzed by the morphological analysis method, and a cross-shape interface was built by the man-machine analysis method. The ergonomic factors of the shape interface were studied from the aspects of riding posture, riding gesture, saddle-horse adaptation, etc. The research model based on saddle shape and ergonomic factors was practical and able to address the interface problem between traditional artifacts and contemporary design. The application of saddle shape could meet the ergonomic requirements for people and horses through design verification. This constructed traditional saddle shape and ergonomics research model systematically demonstrates the saddle shape interface and rider's amenity, comfortableness and other ergonomic factors in several riding states and verifies the design practice.