The personality traits, behavioral qualities and organizational climate created by grassroots leaders are important factors influencing the innovative behavior of grassroots cadres, yet existing research has not clearly elucidated the mechanisms and boundary conditions between the two. Based on self-determination theory and policy entrepreneurship theory, the article explores the influence of a practical leadership style on the innovative behavior of grassroots cadres and its internal mechanism using empirical evidence from a county-level region. The study finds that a practical leadership style has a significant positive impact on the innovative behavior of grassroots cadres; mechanism analysis shows that work autonomy plays a partially mediating role between practical leadership style and grassroots cadres' innovative behavior; and further analysis reveals that both material and spiritual incentives play a positive moderating role in the impact of practical leadership style on work autonomy. In view of this, this paper puts forward the policy suggestions of optimizing the appointment criteria of cadres and improving the training system, paying attention to the psychological perception of cadres and satisfying the demand for autonomy, and opening up the promotion channels of cadres and enriching the spiritual incentives.