A time correction device for a PET system, comprising a detector ring (10), a ring-shaped prosthesis (20), a detection module (30), a data acquisition module (100), a data coincidence module (200), a time shift calculation module (300), and a data correction application module (400). The center of the ring-shaped prosthesis (20) overlaps with the axial and radial center of the detector ring (10). The detection module (30) is located in ring-shaped prosthesis (20). The center of the detection module (10) is at the center of the ring-shaped prosthesis (20). The data acquisition module (100) comprises a data gathering module (110) and an energy filtering module (120) connected to each other. The data gathering module (110) comprises detectors (11) and the detection module (30). The energy filtering module (120) is connected to the data gathering module (110), and receives single-event time information sent from the data gathering module (110). The data coincidence module (200) is connected to the energy filtering module (120), and receives the single-event time information. Time shift calculation module (300) is connected to the data coincidence module (200) so as to provide a shift value of the detectors (11). The data correction application module (400) is used to apply the shift value to the entire system. The device reduces the complexity of a time correction algorithm of a PET system, is easy to operate, and reduces the operational cost of the PET system.
