This article aims to provide a solution of UI (User Interface) of large-scale embedded systems which depends
on the PEG library. UI implementation of embedded systems requires a good portability, that no matter what kind of
target hardware, it does not require any software components with graphical output capability. PEG is abbreviation of
portable embedded GUI, which is a class library. As long as our environment with a C++ compiler and hardware which
can output graphics, you can run PEG, and this precisely is the most important point of the development of embedded
system. This article describes the PEG application in the embedded system, and aim to the large-scale embedded systems
we provides a solution, make the system has good portability, stability and maintainability.