With the high costs of geographic data and its conversion the data transfer barrier becomes a major obstacle in reusing geographic data for geographical information systems (GIS). Data sharing is one of the most effective methods on breaking this barrier which can promote developing and reusing geographical data. It has broken the monopoly of information resources and reduced the "digital divide". So it has great significance in promoting social and economic development. For the lack of researches in data sharing assessment, we proposed a user-oriented method of assessing the data sharing. For the same sharing data, the results of data sharing assessment may be different with different users. So when assessing a sharing data, each user should evaluate firstly and then all results should be considered in the final evaluation result. We firstly design the assessing factors which affect data sharing. In this paper, we make range of sharing, quality of sharing, social benefit, economic benefit, data security and services of sharing as first-grade factors, and on the basis of each first-grade factors, we design corresponding second-grade factors. Secondly, we construct judgment matrixes and calculate weighs of factors by AHP (Analytic Hierarchy Process) and Expert Consultation Method. Thirdly, according to different factors, we use defection subtraction method or method of score standardization in calculating scores of factors. Fourthly, we use the method of weighted sum to calculate the result of data sharing assessment of each user. After getting the results of all users, the average value is calculated as the final score of the data sharing assessment. In this paper, we use the method proposed to assess the data sharing of the government digital map as an example and the functions are implemented by coding. The method realizes the assessment of data sharing, which is benefit in improving the quality of data sharing. It can promote the performance of data sharing and reduce the wasting of resources in data sharing.