A four-channel electron beam planar focusing system is designed to meet the application requirements of the planar integrated traveling wave tube for one-dimensional electron beam array focusing. The calculated results of the axial and transverse components of the magnetic field along the axis are compared with the measured results, which confirms the accuracy of Opera software in calculating the magnetic field distribution. In order to compare with the magnetic field distribution in the electron beam channel of the axisymmetric Periodic Permanent Magnet(PPM) focusing system, a model of the PPM focusing system is established, and the tested results are in good agreement with the calculated results. By comparing the longitudinal and transverse distribution characteristics of the magnetic field in the electron beam channel of the planar focusing system and the axisymmetric PPM focusing system, it is shown that the two focusing systems share the same magnetic field distribution characteristics in the electron beam channel, the ratios of transverse magnetic field component to the axial component are both about 0.11 on the circumference at the same off-axis position, and it is expected that the planar focusing system can achieve good focusing of the one-dimensional array electron beam.