This study utilizes data spanning from 2016 to 2022 concerning Chinese national forest parks and the macro-level data of their respective cities. Employing panel data methodology and selecting forest park tourism revenue and total visitor numbers as indicators, the research aims to gauge the development of forest tourism. The investigation employs a panel model with individual and time-fixed effects to examine the impacts of four key environmental improvement indicators on forest tourism development. The findings reveal that soil quality indicators exhibit no significant influence on forest tourism revenue and attendance. Conversely, air quality and water quality indicators demonstrate a significant positive impact on both tourism revenue and attendance in forest parks. The biodiversity indicator notably influences tourist numbers positively but has no significant effect on tourism revenue. Furthermore, the study uncovers pronounced heterogeneity in the impacts of different environmental improvement indicators on forest tourism across various grades and regions of forest parks. Noteworthy variations are also identified in the impacts of these indicators on tourism revenue and attendance within national forest parks. This research contributes valuable insights into the nuanced relationships between environmental improvements and forest tourism, emphasizing the need for tailored strategies based on the heterogeneity observed among different forest park grades and regions. Furthermore, the study uncovers pronounced heterogeneity in the impacts of different environmental improvement indicators on forest tourism across various grades and regions of forest parks. Noteworthy variations are also identified in the impacts of these indicators on tourism revenue and attendance within national forest parks. This research contributes valuable insights into the nuanced relationships between environmental improvements and forest tourism, emphasizing the need for tailored strategies based on the heterogeneity observed among different forest park grades and regions.