Wetlands play an important role in maintaining the structure, function, and hydrological cycle of oasis ecosystems in arid areas. The comprehensive monitoring and evaluation of oasis wetlands is the basis for accurately understanding the effectiveness of wetland protection policies and strengthening the restoration and protection of wetland ecological environment. Based on the multi-period remote sensing image interpretation from 1975 to 2015 and the benefit transfer method, this study quantitatively analyzed the spatial pattern and ecosystem service value change characteristics of the typical oasis wetlands in the upper reaches of the main stream of the Tarim River, the middle reaches of the Heihe River, and the middle and lower reaches of the Shiyang River in recent 40 years before and after the implementation of wetland protection policy in 2000, and put forward the corresponding management countermeasures of oasis wetlands. The study pointed out that due to people’s pursuit of short-term economic benefits in oases before 2000, the area of oasis wetlands was greatly reduced, and the wetlands landscape was gradually fragmented, resulting in more loss of wetland ecological benefits. Under the implementation of wetland protection policy after 2000, the area of oasis wetlands in the upper reaches of the main stream of the Tarim River and the middle reaches of the Heihe River and their ecological benefits have basically increased, but wetland loss in the Shiyang River oasis was serious and the protection and restoration of its wetlands needed to be further strengthened. The total value of ecosystem services of wetlands was mainly from its regulating service function (accounting for 74%-81% of the total). The wetland area of oases was very small, but the contribution rate of wetlands to the change of total ecosystem service value of oases was large. Therefore, the protection and restoration of wetlands are very important to the stability of oasis ecosystem and the improvement of ecosystem service value.