Starting from the relationship between the Shui Script and the almanac of the Han Ethnic Group, this paper observes further about the Shui Script, and thinks that the fundamental nature of the Shui Script system is its hybridity: the Shui script is generally the same as the almanac of the Han Ethnic Group in the basic principles, the divination of weal and woe, the logic of expression and cultural connotation. Besides, it also reflects the cultural characteristics of the nationality of Shui Ethnic Group, mainly in the spirit system and the selection of auspicious matters. The Shui Script is a hybrid system in cultural connotation. The analysis of the pronunciation, vocabulary and grammar of the Shui Script shows that the language system of the Shui Script is a hybrid system mainly composed of Chinese and mixed with a little Sui language. The system of the Shui character is a hybrid system composed of Chinese characters and Chinese form altered graph as very high frequency common words, and the self-defined characters of the Shui Script as low frequency uncommon words. On the basis of the above research, the nature of the Shui Script is re-recognized: the Shui character can record the content of the Shui Script word by word, it is the word writing, rather than the “phrase character”; the Shui character system is a hybrid system of borrowed words from Chinese, supplemented by Shui nationality’s own characters. From the perspective of language system and recorded content, it is possible that there is no pure self-initiated character, so we should distinguish the two concepts of self-initiated characters and self-defined characters.