1. A system, comprising: at least one storage medium including a set of instructions; and at least one processor configured to communicate with the at least one storage medium, wherein when executing the set of instructions, the system is configured to: acquire a first reference bed location relating to a bed for supporting an object; acquire a first set of reference emission data relating to photons of a first energy level originated from radiation of scintillator crystals of a plurality of detectors, the first set of reference emission data corresponding to the first reference bed location; acquire, at a working bed location relating to the bed, a set of positioning emission data relating to photons of the first energy level, wherein the set of positioning emission data relating to photons of the first energy level originated from radiation of scintillator crystals of the plurality of detectors; and determine the working bed location based on the first reference bed location, the first set of reference emission data, and the set of positioning emission data.