Provided is a synchronization method, which includes: a first device periodically sends a first PSS sequence and first PDSCH control information at frequency points F1 to FN in sequence, where the first PSS sequence and the first PDSCH control information are used for a second device to detect the first PSS sequence and detect the first PDSCH control information; the first device receives signals at frequency points f1 to fM in sequence and detects a second PSS sequence; when the second PSS sequence is detected, the first device obtains second half-frame synchronization information and detects second PDSCH control information according to the second half-frame synchronization information; and when the second PDSCH control information is detected, the first device obtains second frame synchronization information and enters a synchronization state. Also provided are a synchronization device, a synchronization system, and a computer-readable storage medium.