I. Clinical pathway standard hospitalization process for ALL in complete remission 1. The clinical pathway standard hospitalization days are within 21 days. 2.Enter the pathway criteria. (1) The first diagnosis must meet the standard risk and intermediate risk group of patients with childhood acute lymphoblastic leukemia (ALL) disease code (ICD10: C91.002). (2) Achieved complete remission (CR) with induction chemotherapy. (3) When patients have other disease diagnoses at the same time, but do not require special treatment during hospitalization nor affect the implementation of the clinical pathway process for the first diagnosis, they can enter the pathway. 3.It takes 2 days (meaning working days) to perfect the routine examination for admission. (1) Required examination items: ① routine blood, routine urine, routine stool; ② liver and kidney function, electrolytes, coagulation function, blood type, pre-transfusion examination; ③ chest X-ray plain film, electrocardiogram, abdominal ultrasound; ④ fever or suspected infection of a system can be selected: pathogenic microbial culture, imaging; ⑤ bone marrow smear or/and biopsy (when necessary), micro residual lesion detection (when available); (2) Review all tests with leukemic cell infiltration changes before treatment. (3) Patients and family members sign the following consent forms: informed consent for chemotherapy, consent for bone puncture, consent for lumbar puncture and intrathecal injection, informed consent for blood transfusion, and informed consent for intravenous cannulation. (4) Treatment starts within the 3rd day of admission. 5.Treatment plan. (1) Post-remission consolidation therapy ①CAM regimen: cyclophosphamide (CTX) 800-1000mg・m-2・d-1 for 1 time; cytarabine (Ara-C) 75-100mg・m-2・d-1 for 7-8 days; 6-mercaptopurine (6-MP) 60-75mg・m-2・d-1 for 7-14 days. The CAM regimen was repeated once for patients in the intermediate-risk group. mM regimen: high-dose methotrexate (MTX) 3-5g/m-2/d-1 every 2 weeks for 4-5 doses; calcium tetrahydrofolate (CF) 15mg/m-2 once every 6 hours for 3-8 doses, adjusted according to MTX blood levels. 6-MP 25mg・m-2・d-1 for no more than 56 days, with dose adjustment according to WBC. Hydration and alkalinization are required during the implementation of the above protocol. (2) Delayed intensive treatment ①VDLP(D) regimen: VCR 1.5mg・m-2・d-1, once a week for 3 times, maximum absolute amount not exceeding 2mg each time; DNR or Adriamycin (ADR) 25-30mg・m-2・d-1, once a week for 1-3 times; L-asp 5000-10000u・m-2・d-1, for 4-8 times. PDN 45-60 mg・m-2・d-1 or DXM 6-8mg・m-2・d-1, d1-7, d15-21. ②CAM regimen: CTX 800-1000mg・m-2・d-1, 1 time; Ara-C 75-100mg・m-2・d-1, 7-8 days; 6-MP 60-75mg・m-2・d-1, 7 -14 days. Intermediate-risk patients may be inserted into 8-week maintenance therapy (i.e., with an 8-week 6-MP + MTX regimen, as described below). Patients in the intermediate-risk group repeat the above VDLP(D) and CAM regimen once. (3) Maintenance regimen ①6-MP+MTX regimen: 6-MP 50mg・m-2・d-1, continuous oral at bedtime on an empty stomach; MTX 15-30mg・m-2, once a week, orally or intramuscularly, until termination of treatment (2.5-3 years for men and 2-2.5 years for women). Adjust the drug dose in the regimen according to WBC. (2) VD regimen (inserted every 4-8 weeks during 6-MP+MTX regimen): VCR 1.5 mg・m-2・d-1, once, with a maximum absolute dose of no more than 2 mg each time; DXM 6-8 mg・m-2・d-1, d1-7. (4) Prevention and treatment of central nervous leukemia (CNSL): lumbar puncture and intrathecal injection at least 16-24 times. MTX alone or triple intrathecal injection can be used according to the risk group, the specific drug doses are as follows: MTX: age <12 months 6mg, age 12-36 months 9mg, age >36 months 12.5mg; Ara-C: age <12 months 15mg, age 12-36 months 25mg, age >36 months 35mg; DXM: age <12 months 2.5mg, age 12- 36 months 2.5mg, age >36 months 5mg. Children who are diagnosed with CNSL at the initial diagnosis, age <1 year without radiotherapy, age ≥1 year, need to receive the corresponding dose of cranial radiotherapy. 6.Checkup items for review during the recovery period after treatment. (1) Blood routine, liver and kidney function, electrolytes. (2) Organ function assessment. (3) Bone marrow examination (if necessary). (4) Detection of micro residual lesions (when necessary). 7. Treatment during and after chemotherapy. (1) Infection prevention and control: ①Give compound sulfisofazole to prevent Pneumocystis carinii pneumonia; ②Patients with fever are recommended to have immediate pathogenic microbial culture and use antibacterial drugs, cephalosporins (or penicillins) can be used for anti-inflammatory treatment, and those whose fever does not resolve after 3 days can be considered for replacement with carbapenems and/or glycopeptides and/or antifungal treatment; patients with definite organ infection should be selected according to the site of infection and pathogenic microbial (3) Intravenous infusion of gammaglobulin can be used for severe infections. (2) Prevention and treatment of organ damage: antiemetic, hepatoprotective, hydration, alkalinization. (3) Component transfusion: for patients with Hb80g/L, PLT20×109/L or active bleeding, transfuse concentrated red blood cells, single or multi-collection platelets respectively. The indications for transfusion can be relaxed in patients with cardiac insufficiency. (4) Hematopoietic growth factor: Absolute neutrophil value (ANC) ≤ 1.0×109/L after chemotherapy, G-CSF 5μg・Kg-1 ・d-1 can be used. 8. Discharge criteria. (1) Good general condition. (2) No complications and/or comorbidities that require hospitalization. 9. Analysis of the presence or absence of variants and causes. (1) In case of infection, anemia, bleeding and other comorbidities during or after treatment, relevant diagnosis and treatment may prolong the hospital stay and lead to increased costs. (2) If CNSL occurs during treatment, withdraw from this pathway and enter the relevant pathway. (3) Withdraw from this pathway if intramedullary and/or extramedullary relapse occurs during treatment.