Ectomycorrhizae are formed through a symbiotic relationship between fungi and plant roots, and their morphology is an important trait that characterizes the plant's adaptability to the environment. To reveal the distributional characteristics of Populus ectomycorrhizas and their different exploration types of ectomycorrhizas regulate the environmental adaptability of Populus trees, this study collected 77 root samples from nine major Populus cultivation areas in eastern and western China. The morphological features of ectomycorrhizas and the distribution of different exploration types were analyzed. A total of 35 morphological types of Populus ectomycorrhizas were observed in the collected samples, which were classified into three exploration types: contact exploration type, short-distance exploration type, and medium-distance exploration type. There were significant differences in the ectomycorrhizal morphologies between eastern and western China, with the western region having a higher number and morphological diversity of ectomycorrhizal types compared to the eastern region. In the eastern region, Populus ectomycorrhizas were predominantly of contact exploration type, while in the western region, they were mainly of short-distance exploration type, with medium-distance exploration type observed only in the western region. Annual average precipitation was identified as the primary environmental factor affecting the distribution of Populus ectomycorrhizal morphologies, with the colonization of contact exploration type mycorrhizas showing a significant positive correlation with annual average precipitation, whereas the colonization of short-distance exploration type and medium-distance exploration type showed a significant negative correlation with precipitation conditions. Secondly, the physical and chemical properties of the soil also affect the distribution of ectomycorrhizas on poplar trees. The contact exploration type of mycorrhizae exhibits a significant negative correlation with soil pH and a significant positive correlation with ammonium nitrogen and total potassium. In contrast, short-distance exploration type and medium-distance exploration type of mycorrhizae show a significant positive correlation with soil pH and a significant negative correlation with ammonium nitrogen and total potassium. Against the global background of climate warming and soil quality degradation, the findings offer a scientific foundation for future research into the ecological functions of poplar ectomycorrhizae and their adaptive mechanisms to environmental changes.