"Half a River and a General's Merits" takes the life of the famous Southern Song Dynasty general Meng Gong as the main line. From a young general in Zaoyang, to destroying gold and making meritorious services, building the Jingxiang defense line, to supporting the Song Dynasty as a lone pillar, and dying of illness in Jiangling, the panoramic view shows his dual image of "God of War" and "A capable minister in governing the world". The work strictly refers to historical materials such as "History of the Song Dynasty: Biography of Meng Gong", integrates the Song-Mongolian war, imperial party struggles and people's livelihood hardships, highlights the tragedy and helplessness of personal destiny in the grand historical narrative, and ultimately answers a question: when the dynasty is in decline, how long can one person's loyalty and intelligence support half of the country.