Present meta search engines are key-based information retrieve. A plenty of irrelevant information is returned when user search some professional knowledge because Simple combination of key can not express accurately user's purpose. Subject meta search engines solve the problem. Based on the study of present technologies of meta search engines and domain knowledge base, an information retrieve strategy is put forward which is fit for subject meta search engines. It effectively improves efficiency and precision of information retrieve. The main content of this paper are to introduce the key idea and technologies of the retrieve strategy.