The essential significance of scientific metaphor lies in applying the general metaphorical theory to specific interpretations and elaborations of scientific theories to form a methodology of scientific explanation. It is a contextual grasp of objective reality. A given metaphorical context and its grasp of the essence of reality can only be valid when the context is continually restructured. Taking the context as a whole, the methodological characteristic of scientific metaphor lies in the unity of understanding and choice, experience and concepts, semantic structures and metaphorical domains, rationality and irrationality. As a form of thinking based on reasons, scientific metaphor plays an important role in invention, representation, explanation, evaluation, and communication.