Urine out of the white solid, then the possible causes: first, crystalline urine, when certain components in the urine is elevated, such as uric acid, oxalic acid or phosphate is elevated, can produce the corresponding crystals, urination can appear to have crystals. After performing urine collection and precipitation, the lower layer is visible as a crystalline component and the upper layer is clear urine. The crystalline component may disappear after heating the urine, or the crystalline component may disappear after the patient drinks more water. Second, when the patient has a history of urinary stones, extracorporeal shock wave lithotripsy, or after drinking more water and taking oral lithotripsy drugs, small particles of stones may be discharged, which appear as white or brown solid tissue, similar to stone changes. Thirdly, when there is urinary tract infection, pus or shed epithelial tissue etc. is visible in the urine. In this case, when urinating, the presence of white floating material is visible within it. Patients are mostly accompanied by symptoms of urinary urgency and painful urination, and need to undergo a routine urine examination to confirm the diagnosis.