Aiming at the problem that learning interests and motivation of some university students are not strong enough, the influence factors of learning interests are analyzed from the aspects of society, family, school, teacher and so forth. The subtle-type and direct action-type influence factors are proposed. On this basis, the principle of improving the learning interest was given, was discussed. The calculation of normal section flexural capacity of bending member in the course of basic theory of reinforced concrete structure is taken as an example to discuss the method of stimulating students' learning interests in classroom teaching, put forward specific measures to improve students' learning interests, and introduce the application of new technique in classroom teaching.