In order to study on the influence on the optical-optical efficiency and slope efficiency of the mode match of pump and the laser beam in laser diode pumped alkali vapor laser (DPAL), based on the three level rate equation model, instead of the simplified model with average intensity in the medium, the spatial distribution of pump light intensity in the medium is used, and the one dimension DPAL calculation model considering the axial distribution of pump and the laser intensity and the three dimension DPAL calculation model are established considering the distribution of pump in the medium focusing caused by light intensity and the spot radius. The calculation results of the 1D model show that pump threshold in decreasing, the slope efficiency changes little compared with the simplified model. The calculation results of the 3D model show that when the pump mode volume all in the laser the slope efficiency reach the maximum, therefore in the DPAL actual operation, optimization of focal parameters and laser cavity parameters can improve the pump conversion efficiency.