The carcinogenicity of preserved fish has a certain degree of authenticity, but it is not entirely true. Waxed fish is slaughtered by the fresh fish cured air-dried and become, in order to maintain the unique flavor of the fish curing process will be added to a large number of salt and spices, so that the fish may contain a large number of nitrites, people eat, these nitrites will be transformed into a strong carcinogen synthesized in the stomach nitrosamines, if consumed over a long period of time, it is possible to lead to human carcinogenicity. In addition, if the production method, preservation methods and other improper, may be moldy, thus generating more toxic substances with carcinogenicity; in addition, there are more toxic substances in the oil smoke, may also have carcinogenicity. However, this does not mean that as long as people consume preserved fish, it will definitely cause cancer. Generally speaking, if people can strictly control the production and consumption of preserved fish, it usually will not cause cancer. It is recommended to use fresh and safe ingredients, safe preparation methods, and scientific and reasonable preservation and cooking, and it is also not recommended to consume large quantities. If there is any abnormality, suspicion or diagnosis of tumor, it is recommended to go to regular hospitals for comprehensive assessment of the condition, integrating a variety of means to diagnose and assess the disease, and follow the doctor’s instructions to cooperate with the treatment, so as to avoid delaying the condition.