The invention relates to a compensating device for an elevator. The compensating device comprises a guiding device, a fixing device, a stroke switch frame, a limit bow striking frame, a clump weight and a safety device, wherein the safety device comprises safety tongs, a lifting rod, a linkage device, a pull rod and a positioning plate; two safety tongs are fixedly connected at the two ends of the guiding device respectively; the lower end of each safety tongs is fixedly connected with the upper end of the lifting rod; the lower end of the lifting rod is connected with the linkage device; the linkage device penetrates into a reserved hole of the guiding device and can radially rotate; the upper end of the pull rod is connected with the linkage device, and the lower end of the pull rod penetrates into the hole of the positioning plate; and the positioning plate is fixed on the fixing device. In the technical scheme of the invention, when the guiding device moves upwards, the pull rod can move upwards with the guiding device, and after the pull rod moves for a certain distance, the safety tongs can act, so that the guiding device brakes on the fixing device timely and is prevented from rushing out of the fixing device.