Abstract: In 1911, Cai E and Zhu De formed a friendship between teachers and students in Yunnan Military Academy, and then turned into a direct subordinate relationship in the National Protection War. Cai E, as a military academy instructor and battlefield commander, played an enlightening and foundation role in the construction of Zhu De's early military cognitive system and the shaping of revolutionary value orientation. At the military level, Cai E used ' Zeng Hu's military quotations ' to integrate traditional military wisdom and modern Western tactical thinking, and taught Zhu De the concept of mobile warfare and the norms of governing the army with compassion and strict discipline, later exploring the guerrilla tactics of ' defeating the strong with the weak ' and formed the people 's war thought of ' relying on the soldiers and the people '. At the level of personality, Cai E 's firm belief in republicanism, clean and self-disciplined military style, and resolute and unyielding fighting cultivated Zhu De's resolute and simple military character, and deep and profound feelings of home and country. The dual influence strongly promoted Zhu De 's transformation from a progressive young soldier to a revolutionary strategist, laying an early foundation for his future leadership of the new people 's army.

Key words: National Protection War, Cai E, Zhu De, military thought, revolutionary character