The basic theory of calculus is the main content of mathematics courses for non-mathematics majors in colleges and universities, and it is a basic course. Students in the department of mathematics should learn the course of "Mathematical Analysis", which is a professional basic course in the department of mathematics, including calculus, but it is deeper, broader and more rigorous than "Calculus" in theory. For example, real number theory is the theoretical basis of calculus, but it is only available in the teaching materials of mathematical analysis. Calculus and series theory of multivariate functions are also deeper and deeper than calculus in mathematical analysis.