The invention belongs to the ocean observatory field and particularly relates to an anchoring-buoy-based vertical section current observing device. The anchoring-buoy-based vertical section current observing device comprises a support body, at least one fixing clamp and an acoustic Doppler current profiler, wherein the fixing clamp is mounted on the support body and comprises a welding fastening clamp and a movable fastening clamp; the welding fastening clamp is mounted on the support body, and the movable fastening clamp and the welding fastening clamp are detachably connected; the acoustic Doppler current profiler is accommodated inside a space enclosed by the welding fastening clamp and the movable fastening clamp and is fixed and fastened by the welding fastening clamp and the movable fastening clamp. The anchoring-buoy-based vertical section ocean current observing device has the advantages of reliable fixing, simple structure, high cost performance and he like; the anchoring-buoy-based vertical section ocean current observing device is mounted in the center of the bottom of an anchoring buoy, has small inclined angles when the buoy sways and has good precision of vertical section current measurement.