Afforestation and vegetation restoration are difficult in arid, semi-arid and saline-alkali areas. It is urgent to create new varieties of stress-resistant trees to realize the cultivation and utilization of difficult sites. In this paper, the negative regulatory salt and drought stress response alleles of PagHyPRP1 (PagHyPRP1A and PagHyPRP1B), were first obtained and targeted for gene editing in the important cultivated variety Populus alba × P. glandulosa. Moreover, four paghyprp1 mutant lines was obtained with significant improving drought and salt tolerance. Such as mutant lines showed significantly higher plant height, stem diameter, stem weight, root dry weight and root to shoot ratio than WT under salt and drought stress. In addition, studies on the mechanism of drought resistance and salt tolerance on paghyprp1 mutant lines showed that paghyprp1 mutant lines had improved drought and salt tolerance by reducing ROS accumulation, promoting root growth and maintaining root ion homeostasis. For example, mutant lines exhibited higher superoxide dismutase (SOD) and peroxidase (POD) activities proline content and lower accumulation of hydrogen peroxide (H2O2), superoxide anion (O2.-), and reactive oxygen species (ROS); higher Na+ efflux (under salt stress), Ca2+ influx (under drought stress), and H+ influx, less of K+ efflux, while the OE lines showed the opposite results. All above, this study provides candidate resistance genes for forest tree resistance breeding, and obtain four new poplar germplasms with significantly improved drought and salt tolerance. All above provides empirical and a reference for the application of CRISPR/Cas9 to create new germplasm for stress resistance in forest trees.