The anisotropic magnetoresistance film is an important core material for developing the magnetic sen-sors.Here,Ta(5)/MgO(3)/NiFe(10)/MgO(3)/Ta(3) multi-layers (in nanometer) were prepared by magnetron sputtering and further applied to construct a sensor element by combining with the Wheatstone bridge.The 1/f noise of the sensor element was greatly reduced by three orders of magnitude after annealing at 400 ℃ for 7200 s,which was mainly due to the significant microstructural changes dur-ing the annealing.However,when the sensor element was applied to detect the magnetic signal of a magnetic code disk with 512 N-S magnetic poles,the output voltage signal of the sensor displayed a large fluctuation of±0.05 V.In order to reduce the voltage fluctuation,a magnetic sensor chip by using a parallelly arranged multi-path Wheatstone bridges and auto-gain compensation structure was designed,and magnetic sensor elements and the high-performance computing drive module were pre-pared.The output voltage fluctuation of the magnetic sensor was reduced by about 90％ and approached to ±0.005 V.These findings provide an important basis for the practical application of NiFe-based magnetic sensing film materials.