In order to reveal the relationship between tree radial growth and climate in the Northwestern Yunnan Plateau, the study collected tree-ring samples of Pinus densata, Pinus yunnanensis and Tsuga dumosa on Yulong Snow Mountain, established a chronology of the difference between the ring width of three tree species, and analyzed the response and redundancy analysis of the ring index and climatic factors to identify the main climatic factors affecting the radial growth of trees in Yulong Snow Mountain. It provides a basis for the management and protection of forest ecosystems in the region, and for exploring the forest dynamics of Northwest Yunnan under the background of climate change. The results showed that: (1) the established chronology of the width difference between the three tree species has few low frequency changes, and the degree of dispersion is low, and the commonality of the year-on-year change is high, which can represent the annual ring characteristics of the trees at the sampling point; the mean sensitivity of the differential chronology of P. densata, P. yunnanensis and T. dumosa is 0.21, 0.22 and 0.17, respectively, and the overall representativeness of the sample is 0.96, 0.96 and 0.94, respectively, all of which are higher than the threshold of 0.85, indicating that the information in the chronology is representative. (2) In response function analysis, the radial growth of P. densata was significantly and positively correlated with the current February precipitation. The radial growth of P. yunnanensis was significantly and negatively correlated with the mean temperature and maximum temperature of current May, and was significantly and positively correlated with the mean temperature of current October. The radial growth of T. dumosa was significantly and positively correlated with the precipitation of current January and May and the relative humidity of current October, and was significantly and negatively correlated with the maximum temperature of current May. (3) The results of the redundancy analysis showed that the precipitation of current January and February, and The Palmer Drought Severity Index (PDSI) of current May promoted the radial growth of three species, and the correlation coefficient of PDSI was the strongest. The increase in precipitation of current October enhanced the radial growth of P. densata and T. dumosa, while inhibited P. yunnanensis growth. The study believes that the winter precipitation, moisture conditions of May and October precipitation in the current year were main environmental factors affecting the radial growth of three species on Yulong Snow Mountain. If warming and drying trends intensified, it will not be conducive to the growth of the three tree species in the northwest Yunnan plateau, thereby affecting the structure and function of the regional forest ecosystem.