Does the Yin and Yang Family belong to Taoism?

No, Yin and Yang schools were the main schools in the middle of the Eastern Zhou Dynasty and the Warring States Period. It is deeply rooted in China's philosophy, a hundred schools of thought contend and later research, so it has many similarities with Taoism. Related information: Yin-Yang school is one of the main schools in the middle of the Eastern Zhou Dynasty and the Warring States Period. For the purpose of propagating the theory of Yin-Yang and Five Elements, it was named Yin-Yang Family, also known as "Yin-Yang and Five Elements Family" or "Five Elements Family". Sima Tan's The Essentials of Six Classics lists "Yin and Yang Family" as the first of the six classics. Han Shu literature and art is listed as one of the "Nine Rivers". The main representative is Zou Yan of Qi at the end of the Warring States Period. Yin and Yang originally refer to two opposing aspects of things, "One Yin and One Yang is the Tao" (Biography of Zhouyi), and Zhuangzi defined it as the contradictory element contained in qi, "Yin and Yang are also the atmosphere" (Zhuangzi Zeyang). The Yin-Yang school interprets the changes caused by the contradiction between Yin and Yang as mystification, and "observes the news of Yin and Yang deeply and makes circuitous changes" (Historical Records, Biography of Sima Qian, Mencius and Xun Qing).