This study will conduct a prospective single blind controlled study on the clinical efficacy and safety indicators of 50 cancer patients with acute lower limb deep vein thrombosis (DVT). The patients were randomly divided into an experimental group (improved mechanical thrombectomy (PMT) group) and a control group (traditional simple anticoagulation group) using the "envelope method", with 25 cases each. After the end of treatment, clinical prognosis evaluations were conducted on the patient's vital signs, symptoms and signs, lower limb Doppler ultrasound examination, patient PTS score (Villalta score), quality of life score (QOL), etc. at 3, 6, and 12 months. Adverse events, the presence or absence of thrombus recurrence, and re surgical intervention were recorded. This study is expected to propose a new strategy for the treatment of acute DVT in cancer patients, thereby improving the overall level of VTE prevention and treatment.

Inclusion Criteria:

• 1) Between the ages of 18 and 75; 2) Suffering from acute lower limb deep vein thrombosis (DVT) with a duration of less than 14 days from onset; 3) Thrombosis involving the iliac vein, femoral vein, or popliteal vein; 4) The patient has been diagnosed with tumors, including benign or malignant tumors, including surgical or conservative treatment; 5) Sign an informed consent form.

Exclusion Criteria:

• 1) Patients with a history of deep vein thrombosis of the same lower limb in the past; 2) Patients with plasma Cr levels greater than 180umol/L; 3) Patients with contraindications to thrombolytic drugs; 4) Patients with concomitant inferior vena cava thrombosis or simple calf intermuscular vein thrombosis; 5) Patients who are known to be allergic to heparin, low molecular weight heparin, contrast agents, etc; 6) Patients who have participated in clinical trials of drugs or other medical devices that interfere with this clinical trial within the past 3 months; 7) Pregnant and lactating women; 8) Patients with a life expectancy of less than 6 months, or those with other diseases that may cause difficulty in testing or significantly shorten the patient's life expectancy (<1 year), including severe liver disease, cardiac insufficiency, etc; 9) Patients with autoimmune thrombotic disease; 10) Patients who are unable or unwilling to participate in this trial.