Although there are many so-called children's detective books in the book market under the guise of detective, there are few real children's detective novels. Xie Xin has always stressed that we should follow the creative principle of "reasoning by case", that is, we should draw a clear line with those pseudo-children's detective novels. We welcome children's detective stories mixed with fantasy, adventure, magic and other elements, but in the final analysis, they should be detective novels, not other types of novels. China's detective novels started very late, and detective novels in the modern sense came into being in the Republic of China. Children's detective novels are far behind developed countries such as Europe, America and Japan, so the famous detectives in our young readers' minds are all foreign. This situation cannot be changed overnight, and it needs the joint efforts of writers who are interested in children's detective novels. Throughout the contemporary original children's detective novels, we will find that they are often criticized for not paying attention to the rigorous logic of the story, the simple and superficial characterization and the lack of profound themes.