Philosophy is methodology, while mathematics is concrete science. In ancient Greece, philosophy included almost all sciences, and its content was very substantial. A person who can become a philosopher must be an excellent natural scientist; But natural scientists may not become philosophers. However, with the progress and development of human ideological civilization, various specific sciences have become independent from philosophy due to their efforts to find universal laws within their respective research areas, which gradually makes philosophy empty and poor. Today's philosophy is almost rejected by all natural sciences, so it has little to do with mathematics. Logic, reasoning, proof and topology in mathematics are of great help to the study of philosophy. Philosophy is the summary of social science and natural science. Philosophy is indispensable for any discipline, because it is a combination of epistemology and methodology. Mathematics studies quantity, structure and model in logical form; Logic, on the other hand, focuses on what is the authority to ensure the validity of reasoning, and the reliability and completeness of logical reasoning.