Tao Hongjing was obviously a Taoist priest, so why did he call himself a Buddhist Bodhisattva in his later years?

It has made important contributions to the development of Buddhism.

Tao Hongjing: courtesy name Tongming, nickname Huayang Seclusion, a native of Moling, Danyang. Taoist scholars and medical scientists of Qi and Liang in the Southern Dynasties. Tao Hongjing was born into a noble family in the Southern Dynasties. At the age of 10, he read "The Legend of Immortals" to maintain his health; at the age of 15, he wrote "The Chronicles of Searching for Mountains", admiring the life of seclusion; at the age of 20, Emperor Qi Gao introduced him as a king, and later served as the general of Zuowei Palace; at the age of 30, he worshiped Sun Youyue as his teacher and received Talisman diagrams, traveling around famous mountains, looking for elixirs. In 488, the authentic works of Yang Xi and Xu Mi were obtained in Maoshan. In the eighth year of Yongming's reign, he traveled eastward and paid a visit to the lay master. In 492, he resigned from his salary and lived in seclusion in Juqu Mountain, Jurong, where he founded the Maoshan Sect of Taoism.

Emperor Wu of Liang came to the throne and made many invitations but did not leave the mountain. When there are important matters in the imperial court, he is often consulted and exchanges of letters are frequent. He is known as the "Prime Minister in the Mountains". Tao Hongjing inherited the philosophy of Lao and Zhuangzi, combined the concepts of Taoism and Buddhism, and advocated the three religions of Taoism, Confucianism and Buddhism. Following Lu Xiujing, he compiled Taoist scriptures and made great contributions. He compiled the "Shen Nong's Materia Medica", added new medicines from the Wei and Jin Dynasties, and compiled the "Compendium of Materia Medica", which recorded more than 700 kinds of medicines. He has written many works: "Zhen Gao", Huayang Tao's Seclusion Collection, etc. He is good at calligraphy and painting, and is good at playing music, chess, and medicine. He is good at cursive calligraphy and has written calligraphy and painting works such as "Two Niu Picture" and "Mountain Dwelling Picture".

The successor of Shangqing Sect. Traveling around the mountains and rivers, Maoshan was a place for Taoist priests of the Shangqing Dynasty. He promoted the scriptures of the Shangqing Dynasty and wrote Taoist books, especially "Zhen Gao". It narrates the history of teaching the Shangqing Sutra and describes its origin and birth. During his stay in Maoshan, he taught the Shangqing Sutra and worked hard to promote the Shangqing Sutra. He was very famous and had many believers in both the government and the public. Starting from him, Maoshan became the center of the Shangqing sect. Coupled with the descendants of Maoshan after Tao Hongjing, most of whom were learned Shangqing Taoist priests, Maoshan maintained the central position of the Shangqing sect.

Starting from Tao Hongjing, Maoshan represented the Shangqing Sect. People later called the Shangqing Sect the Maoshan Sect, and Tao Hongjing was the founder of the Maoshan Sect. Since Tao Hongjing founded it, through the Sui, Tang, and Song Dynasties, talents have emerged in large numbers, occupying an important position in the Taoist sect.