Quantifying the effects of competition on drought adaptability and ecological resilience in Larix olgensis is crucial for developing adaptive management strategies for its plantations under climate change. In this study, we investigated 36 Larix olgensis plantations at Shengli Experimental Forest Farm in Harbin City, Heilongjiang Province, categorizing the plots into three competition intensity groups: low (CI<2.9, n=45), medium (2.9≤CI<4.8, n=60), and high (CI≥4.8, n=52). Using dendrochronological methods, we assessed the differential responses of Larix olgensis to drought adaptability and ecological resilience across these competition levels. Our findings revealed that the key climatic factors influencing radial growth varied by competition intensity: in the low-competition group, radial growth was primarily limited by monthly precipitation, monthly minimum temperature, and monthly mean temperature during the non-growing season; the medium-competition group was mainly constrained by non-growing season monthly precipitation; and the high-competition group was affected by both non-growing season monthly precipitation and minimum temperature. Regarding drought response metrics, resistance followed the order low-competition > medium-competition > high-competition, while recovery was highest in the high-competition group, followed by the low- and medium-competition groups. Resilience was greatest in the low-competition group, followed by the high- and medium-competition groups. As drought duration extended, resistance significantly declined across all competition levels, recovery exhibited a notable increase, and resilience decreased substantially. These results highlight that non-growing season precipitation is the primary limiting factor for Larix olgensis radial growth, with the low-competition group demonstrating superior adaptability and enhanced drought resistance.