Understanding the long-term dynamics and driving mechanisms of Holocene fire activity is essential for assessing vegetation-climate-fire interactions in monsoon-marginal regions. Here, we present a high-resolution 10.7 ka record of charcoal and Pediastrum from Lake Woniupaozi in the central Great Khingan Mountains, northeastern China. Combined with previously published pollen data, we assess the environmental significance of multiple proxies and explore the mechanisms underlying regional and local fire dynamics. The results show that: (1) Regional and local fires exhibited divergent trends over the Holocene, with enhanced regional fires during similar to 10-8 ka and similar to 3-1.4 ka, and dominant local fires during similar to 10-5.5 ka; (2) The L/W ratio of charcoal is closely linked to arboreal pollen changes and serves as a reliable indicator of woody versus herbaceous fuel input; (3) Variations in Pediastrum body size are species-specific and likely respond to precipitation rather than temperature; (4) Quantitative reconstructions of growing-season temperature (TMar-Oct) based on Pediastrum assemblages are consistent with pollen-based summer temperature trends from nearby sites, highlighting warm conditions in the early and late Holocene. Proxy comparisons reveal that Holocene fire regimes were shaped by distinct mechanisms: (1) Regional fire activity was primarily driven by climate, with warm-dry periods favoring widespread burning; (2) Local fires were influenced by vegetation structure and biomass, with reduced biomass and increased woody cover after similar to 5.5 ka suppressing fire occurrence. These findings highlight the need to consider both future drought trends and vegetation dynamics, as increased surface biomass may elevate local fire risks, whereas forest expansion could help buffer against fire spread and intensity.