A chargedparticle threedimensional momentum mapping analyzer is proposed in this paper. The characteristics are as follows: An axial uniform magnetic field is introduced to constraint the lateral divergence of the charged particles in the system, thus making an analyzer have a comparatively larger angle of particles collection. Positionsensitive detector (PSD) serves as the charged particle receiver, recording both the position and time information of the charged particles. Based on the motion equation of electron in magnetic field, the operating principle is analyzed, and the mapping reconstruction relation among the initial threedimensional momentum information and the position and time information of the charged particles on the detector is given. The superiority over the magneticfieldfree technique is also discussed, and simultaneously the optimum setting of the introduced axial magnetic field is given.