Self-published books usually had to meet the following conditions: 1. Independent Creation: The author needs to create and complete all the content himself without relying on the publishing house or the publishing company. 2. Self-selection of topics: The author needs to choose the direction of publication and decide on the details of the book's topic selection, editing, and layout. 3. Self-pricing: The author needs to decide the price of the book and control the process of publishing and sales. 4. Self-distribution: The author needs to arrange the distribution channels of the book, including printing, logistics, publicity, and other details. The types of books suitable for self-publication usually included novels, essays, poems, and other literary types as well as non-literary types such as history, biography, and popular science. In addition, the author could choose a suitable subject and genre according to his own interests, writing style, and market demand. It should be noted that self-funded publishing required the author to have a certain writing ability and publishing experience. At the same time, it also required sufficient funds and publishing resources. At the same time, the author also needed to have a full understanding of the publishing process and market demand in order to make wise decisions in the publishing process.