A diode-pumped alkali laser (DPAL) provides the significant promise for high-powered performances. In this paper, a mathematical model is introduced for examination of the kinetic processes of a diode-pumped cesium vapor hollow-core photonic-crystal fiber (HC-PCF) laser, in which the cesium vapor is filled in the center hole of a photonic-bandgap fiber instead of a glass cell. The influence of deleterious processes including energy pooling, photo-ionization, and Penning ionization on the physical features of a fiber DPAL is studied in this report. It has been theoretically demonstrated that the deleterious processes cannot be ignored in a high-powered fiber-DPAL system.