In the detection mission of P-40 fighter plane falling in Dianchi Lake Salvage Team, the fighter plane falling in Dianchi Lake was detected and the location of the fighter plane falling was determined. HRU100-24 aeromagnetic equipment was used to quickly retest the position of the aircraft, the target signal was 20nT, the water depth was 6 meters, and the aircraft was buried in the lake bottom soil layer of 18.5 meters, and CCTV recorded the scene.