Abstract: To further improve the public's enthusiasm for participating in afforestation in the context of carbon neutrality, based on the model of knowledge, attitude and practice (KAP) and the theory of planned behavior (TPB), this paper adopted questionnaire survey and structural equation model to empirically analyze the motivation and behavior choice of public participation in the existing mode of "Internet + Tree Planting" in China: the enterprise-led model represented by "Ant Forest" and the government-led model represented by "Internet + National Voluntary Tree Planting". The results are as follows: Environmental cognition and perceived behavioral efficacy significantly and positively affected the public participation attitude; Attitudes and perceived behavioral efficacy significantly and positively affected public participation intention; Perceived behavioral efficacy can directly or indirectly stimulate the public's participation willingness. Subjective norms have no significant influence on public participation attitude and willingness, that is, external environment can not effectively stimulate public participation behavior. Participation willingness plays a significant role in the public participation behavior under the two models, but the path coefficient of "Ant Forest" behavior was greater than that of "Internet + National Voluntary Tree Planting". Finally, "Internet + Tree Planting" should promote public participation by popularizing environmental knowledge, creating integrated platforms and opening interactive channels.