The invention provides a Chinese character input method and device based on binary syllabification. After a signal triggered by a key is received, input information corresponding to the received signal is determined by inquiring the mapping relation between the input information and the signal. In the mapping relation, single-letter consonants correspond to signals of corresponding keys, double-letter consonants zh, ch and sh correspond to signals of the keys A, V and E respectively, vowels are divided into the six types of a, o, e, i, u and u according to the initial letters of the vowels, and the vowels of the same type are arranged on adjacent keys, wherein two similar but not repeated vowels are arranged on each of the nine keys of T, Y, O, J, L, Z, X, C and M. The vowels are arranged according to the use frequency of the vowels, and the vowels with high use frequency are sequentially arranged on keyboard keys easy to click to increase the input speed of Chinese characters. Thus, by setting the mapping relation, a user can conduct memorizing conveniently, Chinese characters can be easily input efficiently, and the Chinese character input efficiency of the user can be greatly improved.