This paper studies the application programming interface in configuration software. Based on comprehensively considering softwares application, a mini-message bus configuration languageMMBCL language is designed by using C language, whose compiler and development environment are fulfilled. The designing, syntax analysis, semantic analysis of MMBCL are deeply discussed. This configuration language is simple, similar to C language, easy to write, consistent with industrial control standard. And it has successfully applied to the industrial project and proves the efficiencies of the configuration language and the compiler.