The concepts of social context and scientific context have been put forward in the paper and they have been used in revealing the developed and developing mechanism of science itself and scientific knowledge.

Both the model of register analysis developed by Halliday and that of genre analysis by Martin are used to do context analysis in Systemic Functional Linguistics,but they have differences in the basic definitions and theories.

After comparing with the way of translation and the quality of some translating software,we add the function of learnign and context analysis to our program.

Our goal in translation is to decode the fuzzy points of a discourse, and by means of context analysis.

In accordance with the method of contextual analysis, science communication should transfer from deficit model to contextual model.

As the central studying method of contextualism,contextual analysis is the sets of syntactical analysis,semantic analysis and pragmatic analysis.

Based on PRETCO(Practical English Test for College Students) & contextual analysis,we can get a deeper & better understanding of word meaning and syntactic,semantic & pragmatic meanings,and thus help cultivate students translation ability.