Abstract: Words separating is an important step in natural language understanding. Since the language problem is also one of the most important problems of psychology, so from the point of view of cognitive psychology and development psychology, words separating is regarded as a step of perception problem occurring in language information processing. Representation of perception, data driven process, and conception driven process are adopted into the research of words separating. At the same time taking into account the psychological procedure of language development, the inductive learning is designed, and the performance of the language understanding system is progressed by the term of evolution, so the happening of knowledge acquisition bottleneck can be avoided when a natural language understanding system is constructed.