The ecotourism industry plays a crucial role in promoting the realization of ecological product value within national parks, with ecotourists serving as critical participants in this process. This paper takes the Tangjiahe Area of Giant Panda National Park as an example. It builds a structural equation model by expanding planned behavior theory to explore the factors influencing ecotourists' attitudes and behaviors toward ecological product purchase and to verify the different influences of environmental concern and destination attachment on these behaviors. The findings reveal that (1) Environmental concern positively influences behavioral attitude, subjective norm, and destination attachment; however, it does not directly promote purchase intention or behavior. (2) Destination attachment positively impacts behavioral attitude, subjective norm, perceived behavioral control, purchase intention, and behavior. (3) Behavioral attitude, perceived behavioral control, and destination attachment significantly and positively affect the purchase intention of ecological products. (4) Both perceived behavior control and purchase intention directly and positively influence purchase behavior, with intention showing the most significant predictive power. (5) Groups with higher and general levels of environmental concern show significant negative and positive differences, respectively, in specific pathways of influence.