In clinical work, after some tumor patients are cured, clinically cured or controlled through various effective treatments, after a period of time, the tumor recurs again, which brings pain to the patients and their families again, and the recurring tumor is more difficult to treat than the original one. So, how to prevent tumor recurrence? At present, modern medicine advocates that tumor patients should insist on anti-recurrence treatment for more than five years after the clinical symptoms disappear through surgery, radiotherapy or high-dose chemotherapy, generally four courses of chemotherapy for 30-40 days each time every year on the basis of the original cure; meanwhile, they should try to avoid the factors that cause tumor recurrence, strengthen physical exercise, increase immunity and review regularly. However, it is difficult for many patients to achieve the above requirements, and the effect is not ideal. At present, there is no unified understanding of the prevention of recurrence and metastasis, so naturally, there is no way to talk about it. After thinking about this problem for more than a year, I finally understood what is the more reasonable and appropriate concept of tumor, and the idea of natural treatment and recurrence prevention became clear. At present, the concept of tumor is “tumor is an abnormal lesion formed by the loss of normal regulation of the growth of a cell in the local tissue at the genetic level under the action of various carcinogenic factors, resulting in its clonal abnormal proliferation”, which is quite vague. I currently define tumor as a xenobiotic formed by the mutation and proliferation of autologous cells in the region that are not inhibited by the recognition of local immune cells after the alteration of the local internal environment. Here, firstly, the seed and soil doctrine is clarified (although Western medicine has proposed this doctrine, the theory has not yet broken through and the clinical practice has not yet started), and secondly, because the autologous cells mutate and the local immune cells cannot recognize the mutated cells to destroy them. Therefore, from this point of view, the treatment and prevention of tumor will be very clear, which requires three steps to start the treatment at the same time: First, change the “internal environment”, which is the specialty of TCM! According to TCM, the occurrence of tumor is not without reason, it is related to the innate endowment of human body, lifestyle, bad hobbies, emotions, etc. Each part and each internal organ is a specific cause of tumor. Therefore, traditional Chinese medicine can change the internal environment by adjusting the internal organs and the characteristics of the tumor site, and change the bad lifestyle, suggesting patients to make changes in diet and living. Secondly, to improve the local “immune function”, this aspect is the “acupuncture, medicine and moxibustion targeted immune tumor suppression” that I have proposed many times in QQ.com “Hall of Famous Doctors”, “Health News” and “Beijing Daily”. “Through targeted acupuncture, moxibustion and external application of Chinese herbal medicine to stimulate local qi and blood, unblock the meridians and improve the “immune function”; first and secondly, to maximize the restoration of positive qi, so that “positive qi can be kept inside and evil can no longer dry up”. Thirdly, anti-cancer, i.e. taking oral anti-tumor Chinese medicine and proprietary Chinese medicine, aiming to destroy the remaining tumor cells after treatment or inhibit the further development of undetected tumor cells. Only in this way, it is possible to prevent the recurrence and metastasis of tumor. The treatment of tumor in Western medicine is mostly in the third anti-cancer aspect, and the focus is relatively limited. They do not know enough about “changing the internal environment” and “improving local immune function” and do not apply enough, so they are obviously insufficient in preventing tumor recurrence.