For 24-hour urine collection and preservation, firstly, prepare a clean container, and secondly, collect all urine excreted for 24 hours and add preservative and seal it at the first urination. First, the patient should prepare a clean and tidy container with as large a volume as possible, 4000 ml or more is recommended. Second, the patient should urinate once at some point during the day, noting that the first urination does not need to be collected, but all urine for the next 24 hours needs to be collected in the container. In addition, while collecting the urine for the first time, you need to add the preservative given by your doctor into the container and shake the urine well. The container is then sealed to prevent evaporation of the urine from affecting the sampling. Once the collection is complete, just wait for the hospital professionals to pick it up. To summarize, patients must strictly follow the requirements of 24-hour urine collection, and should consult their doctors if any problems arise during the period.