The relevance of the article is determined by the requirements of the society to train a specialist in the context of the global social challenges in relation to future specialists in the field of foreign language. The historical analysis of ideas, concepts, paradigms in the training of a future foreign language teacher allows us to identify modern goals, content and training technologies for the modernization of educational practice in the framework of future foreign language teachers' training in the higher education system. In this study, the aspects related to the prognostic and final diagnostic components of the STREAM technology model are presented, criteria and parameters for measuring the level of critical thinking abilities in future foreign language teachers are highlighted. The test materials used to diagnose the level of critical thinking ability formation in future foreign language teachers are described.