With the revision of the high school physics curriculum standards, further requirements of the core literacy cultivation for the high school students have been made. By studying university physics knowledge, high school teachers can cultivate the ability to understand and solve physics problems with higher-order thinking for the students, and then the internalization of the core physics literacy will be realized. Comparative research of textbooks is an important means of optimizing the teaching process. By applying comparative research methods, this paper compares three aspects of knowledge points, exercises, and experiments between the commonly used college physics textbook (edited by Cheng Shouzhu) and the People's Education Edition high school physics textbook's thermodynamics section. It proposes the connectable content between the two sets of textbooks. It will provide foundation for frontline physics teachers to design and implement connected teaching.