The main precautions during chemotherapy for rectal cancer include the following aspects, namely, regular medication, regular review, dietary control and daily conditioning. 1. Regular medication: the medication should be applied according to the instructions of clinicians, so as to maximize the therapeutic effect of medication and minimize the side effects of medication. 2. Regular review: During the treatment period, we need to regularly observe the treatment effect of the lesions through imaging examinations and blood tests, and adjust the treatment plan in time if any abnormality is found. 3. Dietary control: avoid eating spicy, stimulating and greasy food during the treatment period, pay attention to replenish essence protein, eat more vegetables, fruits and other food to regulate the gastrointestinal tract. 4. Daily regulation: pay attention to regular work and rest, avoid staying up late, must pay attention to relaxation, the physical condition to the best. During the treatment period, we should pay attention to closely observe the condition of the lesion area, and find that the treatment effect is not good, communicate with the doctor in time, and carry out standardized treatment under the guidance of the clinician to prevent the delay of the condition.