Abstract: Philosophical perspective is an early and long-lasting part in Sun Yu's study on Lu Xun.He creatively compares Lu Xun and Kant, pointing out they are similar in underlining the limitation of cognition.Sun Yu emphasizes skepticism as Lu Xun's core thought, and its significance in cultural history.He deeply interprets Lu Xun's thought and works, by means of the thought of"subjectivity".He also stresses that traditional"master-slave" culture is the barrier of"inter-subjectivity".Above all, the use of philosophical perspective in Sun Yu's study, is not pure knowledge production, on the contrary, is full of vitality and academic value.