Abstract: Faced on the rapid development of global Internet and the information technology,it is possible to communicate each other using accessible information of Internet in the world.The technology and platform of across languages instant communication is short,for constrain of labor cost and language retrieval technology.This paper proposed a extensible cross-languages model and implement method of online interactive platform construction,based on across languages knowledge base design,knowledge retrieval and translation work together technology.After using this method,the mono-language retrieval will replace multi-languages retrieval,which make visitors from different countries can use their own familiar language through the Internet and online customer service staff to communicate and exchange.