English reading teaching plays an extremely crucial role in English teaching, but there are a lot of problems in traditional English reading teaching classes. The result is unsatisfactory and teaching efficiency is low. The constructivist learning theory can promote the improvement of students’ English reading ability and develop their core competence. The constructivist learning theory emphasizes that students are the controllers of learning. Teachers need to create text-related situations which are conducive to students activating new schema associated with the previous schema. This step can promote the meaningful construction of knowledge. This theory also argues the importance of cooperation, allowing students to work with group members to complete the tasks. This essay introduces the definition, principles, development and advantages of constructivist learning theory. The essay focuses on the application of the constructivist learning theory in various stages of English reading teaching in senior high school. Based on the analysis of the situation of English reading teaching in senior high school, this essay aims to explore the enlightenment of the constructivist learning theory to English reading classes in senior high school and solve some current problems existing in traditional reading teaching in senior high school which can improve teaching efficiency and students’ English core competence.