This paper is based on a set of Helmholtz coil axial plane magnetic field measurement device developed, combined with the PASCO experimental platform, using a two-dimensional magnetic sensor to measure the three-dimensional magnetic field component of any point on the axial plane. The magnetic field of Helmholtz coil is calculated through MATLAB programming. The comparison between the numerical calculation results and the experimental measurement data shows that the error is less than 3.0%. This experimental device has high accuracy, and the numerical calculation results can be verified by precise experimental measurement. The work in this paper further optimizes and expands the content of university physics experiments.