The invention provides an acquisition method and an acquisition device of PON network resource data, and the method comprises the following steps: aiming at each port of a final-stage optical splitter, executing the following operations: based on optical layer link monitoring information of each ONU corresponding to the final-stage optical splitter before and after bending an optical fiber of theport, determining a target ONU of which changing situation of the optical layer link monitoring information satisfies a set condition; and recording a corresponding relation between the port and the target ONU. With the method and the device provided by the invention, the corresponding relation between the ONU and the port of the final-stage optical splitter can be determined.