The continuous development of embedded technology has emerged an increasing demand of internet-based embedded software. The current existing tools only offer coarse-grained network detection, in other words, they don’t satisfy the refining detection standard for the convenience of developers. This paper begins with analysis into defects of the current network detection methods and tools with deep insight from the Netfilter of Linux kernel and protocol stack for packet processing technology, it then proposes a fine-grained network detection method, with which we build up an embedded-software-network detection tool for digital-home-appliances. The built tool can operate real-time and fine-grained monitoring. An experiment has been performed in the final section of the paper to prove the accuracy of the method.