In order to understand the current situation of Chinese students' reading competence and improve students' reading comprehension, this study researched 56796 fourth grade students from 283 primary schools in Mainland China through the quantitative method. Firstly, this study discussed the reading engagement of Chinese fourth grade students and reading instruction of Chinese languages teachers in the natural state. Secondly, this study analysed the effects of school-level reading instruction and students-level reading engagement on reading comprehension through a hierarchical linear model. The results showed that: (1) Chinese fourth grade students have a high level of reading engagement, but there are obvious group differences; (2) Chinese language teachers prefer choosing stimulating tasks rather than rote tasks in reading classroom, but the text-centered teaching approach is still common for Chinese language teachers; (3) Reading engagement and reading instruction have positive effects on students' reading comprehension. And there is an interactive effect of emotional engagement and reading instruction on reading comprehension. For students with low emotional engagement, the higher frequency of reading instruction, the greater positive effect of emotional engagement on reading ability.