Location Based Service(LBS) is a new wireless increment service, which can provide mobile users locationbased information services through the mobile network and has huge market potential. The system platform of LBS has a direct bearing on the quality of commercial services. From the actual conditions of application deployment, this paper expatiates how to design the platform based on the facade pattern in J2EE, which can avoid tight coupling between the accesslayer and the businesslayer and make the module development more efficient and  flexible. A simulation test for the platform has proved the feasibility of the design, which  meets the basic requirements for commercial operation.