Nd3+-doped phosphate laser glass with the composition of 64P205-5.9A12O3-7.1K2O-19BaO-4.0Nd203 (Wt%) was prepared by means of reaction atmosphere dehydration process. The dehydration efficiencies of O2+POCl3 and O2+SOCl2 were studied, and the influence of identical dehydrator on the fluorescence lifetime of the prepared Nd3+-doped phosphate laser glass with different dehydration time, dehydration temperature and bubbling flux were also analyzed. The results showed that the dehydration efficiency of POCl3 overmatches SOCl2; the dehydration rate is the fastest at the initial bubbling stage, dehydration temperature raising benefits eliminating moisture; but it′s more appropriate to dehydrate under 1 200℃ due to influence from smelting equipment and process; prolonging the dehydration time and increasing the bubbling flux are beneficial to improving dehydration efficiency; dehydration efficiency of glass is mainly influenced by the interface reaction between OH and dehydrator; fluorescence lifetime is increased with the extension of the dehydrate time and it tends to a stable valve finally; there is an optimum value for bubbling flux that is 0.8litres every minute in the experiment.