Globally Important Agricultural Heritage Systems (GIAHS) is a type of heritage with rich ecological and socio-cultural values, which reflects the long-term harmonious relationship between people and land. Tourism development has been recognized as an important strategy to promote the dynamic conservation and the realization of the ecological value of such heritage systems. However, how tourism can be formed to meet the needs of both the supply and the demand of tourism and to fully realize the ecological value of agricultural heritage systems remains to be further explored. From an integrated perspective of supply and demand, this paper takes Aohan Dryland Farming System, a designated GIAHS in the Inner Mongolian of China, as an example. Both qualitative and quantitative research methods were engaged for data collection, including semi-structured interviews with residents and the village management and questionnaire surveys with residents and tourists. Recognition of the ecological value of Aohan Dryland Farming System, willingness to participate in tourism, and needs of community residents and tourists are measured and compared. Drawing on research results, strategies to realize the ecological value of agricultural heritage systems through tourism are identified. Three key results are identified in the study. (1) Both residents and tourists demonstrate low overall recognition of the ecological value of Aohan Dryland Farming System. (2) Tourists show stronger willingness to participate in local food tasting, ecological millet tasting and purchasing, and museum visitation. In terms of their willingness to pay, farmhouse accommodation, tasting local foods, leisure activities, and educational activities are ranked high. (3) Community residents have higher willingness to participate in providing traditional food and accommodation services for tourists. Individual livelihood assets and capacities, organizational models and the distribution of benefits are recognized as the main factors restricting effective community participation. Based on the above results, this paper puts forward three suggestions to promote the tourism realization of the ecological value of Aohan Dryland Farming System. First, the breadth and depth of ecological value interpretation should be extended to enhance the value recognition of residents and tourists. Second, tourism products need to be enriched and diversified to promote the matching between the supply and the demand. Third, the cooperative-driven community participation in tourism needs to be established. Through an integrated analysis of the supply and the demand, the study expands the research perspectives on the tourism realization of the ecological value of agricultural heritage systems, which can provide references for the dynamic conservation and sustainable tourism development of Aohan Dryland Farming System and other agricultural heritage systems in China and abroad.