Wang Guowei, a famous scholar, once said that "realm" means that when a person has the realm of character and knowledge, he has a kind of power. The power of this "realm" can nourish the soul, penetrate time and space, and be peaceful for a long time. Mr Teng Da Chun is such a person. He explained the connotation of "realm" for us with his own life portrayal. Teng is a master of educational history in China and a giant of educational history research abroad. He is not only an expert, but also a scholar. He is also an educator and moralist. From his life course and struggle footprint, we can realize the lofty "realm" of a generation of masters in academic attitude and personality cultivation.