The invention discloses a pretreatment method, a preservation method, an automatic treatment system and a detection method for a urine sample, and directs to the technical field of biological detection. The pretreatment method comprises subjecting a urine sample after protein lysis to a reductive alkylation treatment, followed by protein enrichment and enzymolysis. The protein enrichment is performed on the sample after the reductive alkylation treatment using a PVDF filter plate for protein enrichment; The invention also provides an automatic treatment system and an automatic sample treatment method. The treatment system greatly reduces the labor intensity of people, is beneficial to facilitate the treatment efficiency of urine sample treatment, meets the requirements of high-flux and automated pretreatment of the proteomics, and accommodates the reproducibility and flux of current clinical needs.