This article is a short proposal methodology of the professional / technical bilingual dictionary. First of all, gives a brief outline of the issues from the diachronic perspective, the second part is devoted to the synchronous approach to handle the lexicon. In the recent ten up to fifteen years (under the influence of the information technology development), the methodological approach in the field of bilingual lexicography has changed in the structuring of the bilateral dictionary entries (new methods of data collection, computer processing and evaluation, etc.).