Yang hailed from Yanzhou 兖州 (modern Yanzhou, Shandong), and was editing clerk (jiaoshu 校書) in the Astrological Commission (taishiyuan 太史院), then investigating censor (jiancha yushi 監察御史), and finally director of studies (siye 司業) in the Directorate of Education (guozijian 國子監). He also wrote the books Liushu shuoyuan 六書溯源 and Shuxue zhengyun 書學正韻, both also dealing with characters and their pronunciation.
The 20-juan long book Liushutong was presented to the throne in 1308 and was subsequently printed on imperial order and distributed throughout the empire.
In his book, Yang Huan attempts to demonstrate how characters are related (tong 統) to each other by the system of the six types of characters (liushu 六書), which he divides into smaller categories.
Ideograms (xiangxing 象形) consist of 10 classes (lei 類, like words related to Heaven, Earth, geography, man, clothes, animals, etc.), huiyi 會意 characters (composed of two other characters and their meaning) of 16, like movements in the sky, the shape of the earth, social relations, human qualities, numbers, colours, movements, and life and reproduction. Zhishi 指事-type characters (pointing at parts of objects or at concepts) of 9, like directly "pointing at objects", "suggesting shape by shape", "suggesting meaning by meaning", "suggesting shape by meaning", etc. Characters of the type zhuanzhu 轉注 ("mutual explanation") were dividable into 18 classes. The large group of xingsheng 形聲-type characters (combinations of meaning and sound) consisted of 18 classes, and jiaxie 假借 "loan" characters of 14 (like loan character by sound and meaning, by meaning, by sound, by close sound, abbreviation, by character similarity, etc.).
The classification of the characters of the types xiangxing, huiyi, zhuanzhu and xiangxing correspond to that described in Dai Tong's 戴侗 (1200-1285) book Liushugu 六書故, while those for the zhishi 指事 and jiajie 假借 types have been created by Yang Huan himself. Yet his method of classification is very inconsistent. For each character he provided the four writing styles of ancient characters (guwen 古文), large seal script (dazhuan 大篆), "bell-and-tripod script" (zhongdingwen 鐘鼎文) and small seal script (xiaozhuan 小篆).
Yang Huan was very fascinated by large seal-script characters, a style he rated as most useful to understand the meaning of a character, yet for daily use the small seal script was more comfortable, as he said. Yet this style was often corroborated in later ages. The descriptive bibliography Siku quanshu zongmu tiyao 四庫全書總目提要 criticizes Yang Huan for perpetuating the mistakes of Dai Tong's book and his chaotic handling of ancient styles. It is nevertheless included in the imperial series Siku quanshu 四庫全書.