The invention provides a supporting mechanism and a centring device comprising the supporting mechanism. The supporting mechanism is used for supporting a hook of a sky train and comprises a supporting assembly and a positioning assembly, wherein the supporting assembly is arranged on a centring mechanism in a telescopic mode so as to be used for supporting the hook, and the positioning assembly is arranged on the supporting assembly so as to be used for positioning the hook. According to the supporting mechanism, the problem that positioning and supporting are conducted on the hook of a sky train by a supporting mechanism in the prior art inconveniently is solved.