This document discusses research on a cloud security communication firewall based on the Android platform. It begins with an introduction on smartphone communication security and firewall models. It then outlines the design of the firewall software system, including modules for user interface, call filtration, SMS filtration, data storage and transmission. The document describes the process for call and SMS filtration. It concludes that the firewall system based on cloud security technology can lower operating costs and benefit from the client-server architecture.