In this paper, the time-dependent Fokker-Planck equation of α particle angular density distribution function in one-dimensional spherical symmetric D-T plasma is seperated to two equations relevant to velocity and ordinates when discreted in time domain. The velocity variable in these two equations is treated by multigroup method, while the ordinate variables are treated by finite element method, thus two finite element equations are obtained. By couple calculation of these two equations, the variation of α particle angular distribution function vs time is calculated numerically. Based on these results, the time and space distribution of energy deposition rates of αparticles to ions and electrons in plasma are calculated respectively, and the total energy deposition rate of αparticles to background plasma is also obtained.