There is no fastest way to regulate immunity specifically by eating after kidney cancer surgery, which needs to be regulated under the guidance of clinicians. It mainly includes drug control and life regulation. 1. Medication control: Thymopentapeptide is commonly used to enhance immunity after surgery, which can be applied regularly under the guidance of clinicians. 2. Life regulation: pay attention to adjusting the diet, matching the nutrition, pay attention to supplementing the essence protein (such as lean meat, fish, eggs, milk, etc.), do not eat too stimulating, too cold food, adjust the function of gastrointestinal tract and promote the absorption of nutrients. In addition to strengthening immunity through medication and diet, one should also pay attention to strengthening physical exercise and outdoor activities, but one should pay attention to avoiding one-time exercise that is too strenuous. To sum up, once there is low back pain and physical condition decreases during the recovery period after kidney cancer surgery, it is necessary to consult doctor in time and carry out standardized treatment under the guidance of clinicians.