The utility model relates to a device for a laboratory for simulating nitrogen and phosphorus release of water body sediments. The device comprises a speed-adjustable pump, a waterbath thermostat, a heat-insulated columnar releaser, a heat-insulated overlying water circulator and an experimental condition detecting system, wherein sealing covers are arranged at the tops of the heat-insulated columnar releaser and the heat-insulated overlying water circulator; the experimental condition detecting system is arranged above the sealing covers of the heat-insulated columnar releaser and the heat-insulated overlying water circulator and passes through the sealing covers to be inserted into the heat-insulated columnar releaser and the heat-insulated overlying water circulator; a speed-adjustable stirrer is arranged in the heat-insulated columnar releaser; a water valve at the middle of one side of the heat-insulated columnar releaser is connected with another water valve positioned at one side of the bottom of the heat-insulated overlying water circulator through a water guiding pipe and the speed-adjustable pump; the heat-insulated columnar releaser is connected with a temperature modulator; and the water valve at the lower part of one side of the heat-insulated columnar releaser is connected with the water valve at the upper part of the heat-insulated overlying water circulator through the water guiding pipe. The device provided by the utility model also can be used for the laboratory for carrying out the research of influences of simulating different conditions (temperature, DO (Dissolved Oxygen) and pH (Potential of Hydrogen)) to the nitrogen and phosphorus release of the sediments.