Recently, many cities in China have developed geographic information public services platforms to assist decision-making and facilitate the life of citizens. However, the disadvantages of the traditional platform are more and more obvious. In order to address these challenges and deficiencies, we propose a cloud computing architecture for the geographic information public services platform, which can provide the basic map service and spatial analysis functions to supply the demands of some governmental departments and the public. A four-layer model is designed for this architecture, which includes a resource layer, a virtualization layer, a management layer and a public geographic information services layer.