Provided are a tetrahydroisoquinoline derivative, a preparation method therefor and an application thereof in medicine. In particular, provided are a tetrahydroisoquinoline derivative represented by general formula (I), a preparation method therefor and a pharmaceutically acceptable salt thereof as well as use thereof as a therapeutic agent, in particular as an angiotensin II type 2 receptor (AT2R) antagonist, wherein definitions of substituent groups in the general formula (I) are the same as definitions in the description.