Abstract: Based on the single particle theory and integral arithmetic, the ALFA code is exploited to analyze the energy deposition of non-thermal alpha particles in cylindrical and spherical magnetized targets. It is found that, the energy deposition of alpha particles in the cylindrical magnetized target is larger than that in the spherical one under the same background magnetic field, D-T plasma density and plasma temperature; there is a work region of magnetic field for average energy deposition of alpha particles. If the magnetic field exceeds the work region, the average energy deposition stays at a constant nearly. As for the different geometry scale, the work region of the magnetic field affecting the energy deposition of alpha particles appears different. The alpha particle energy deposition increases with the D-T plasma density.