NOVELTY - Partial nitrification of digested sludge achieved by a device, is claimed. The device comprises a sludge digestion water tank, a water pump, a short-range nitrifying nitrous oxide reactor and an air compressor, where the sludge digestion water tank is provided with an emptying tube and an overflow tube. The short-range nitrifying nitrous oxide reactor is seal type sequencing batch reactor. A top part of the reactor is provided with a seal cover and nitrous oxide collecting tube. An upper wall of the reactor is equipped with a sampling port and discharging port and a water outlet tube.    USE - The method is useful for partial nitrification of digested sludge (claimed).    ADVANTAGE - The method is capable of partial nitrification of digested sludge with reduced emission of nitrous oxide.    DETAILED DESCRIPTION - Partial nitrification of digested sludge achieved by a device, is claimed. The device comprises a sludge digestion water tank, a water pump, a short-range nitrifying nitrous oxide reactor and an air compressor, where the sludge digestion water tank is provided with an emptying tube and an overflow tube. The short-range nitrifying nitrous oxide reactor is seal type sequencing batch reactor. A top part of the reactor is provided with a seal cover and nitrous oxide collecting tube. An upper wall of the reactor is equipped with a sampling port and discharging port, a water outlet tube, dissolved oxygen probe and a pH probe. A dissolved oxygen meter and a pH meter are connected with corresponding probes. A bottom part of the reactor is provided with an emptying tube, and a aeration system. The aeration system is connected to the air compressor through a gas flow meter. The aeration system is connected to the sludge digestion water tank through the water pump. The short-range nitrifying nitrous oxide reactor is connected to a sodium carbonate solution container to add a sodium carbonate solution into the short-range nitrifying nitrous oxide reactor through a pump.