Disclosed is a kinase inhibitor, comprising a compound of formula (I) or a pharmaceutically acceptable salt, solvate, ester, acid, metabolite, or prodrug thereof. Also disclosed are a pharmaceutical composition comprising the kinase inhibitor and uses and methods for inhibiting the activity of one or more tyrosine kinases selected from MST1 and a mutant thereof in a cell or subject and for preventing or treating a disease related to MST1 or a mutant thereof in a subject by using the compound or composition.