The invention discloses a water body sediment sampling device capable of controlling the volume of a sample. The device comprises a sleeve, an upper cove, a bottom plate and a bottom plate control rod, wherein the upper cover is screwed with an opening in the upper part of the sleeve through a thread; a storage battery, a low-speed direct-current servo motor, a threaded sleeve, a sampling barrel and a threaded transmission rod are arranged in the sleeve; the threaded sleeve is fixed inside the sleeve and is in threaded connection with the sampling barrel, and an opening of the threaded sleevefaces downwards; the threaded transmission rod penetrates through the threaded sleeve, a drive bearing and a transmission gear, and the tail end of the threaded transmission rod is fixed on the outerside of the bottom of the sampling barrel; the transmission gear is meshed with a motor gear, and the motor drives the motor gear to rotate; the upper cover is provided with a console, when the uppercover is screwed with the opening in the upper part of the sleeve, the console, the storage battery and the low-speed direct-current servo motor form a loop; a fixing plate is arranged on the lower part of the outer side of the sleeve, a rotating shaft is arranged on the fixing plate, and the bottom plate control rod is fixedly arranged on the rotating shaft; the bottom plate is connected to the rotating shaft and is arranged on the fixing plate; and a plurality of bottom plate small holes are arranged in the bottom plate. According to the device, semi-automatic sample collection can be realized.