Catheter-related DVT under the setting of TTP or TTP recovery stage may be presented as a more fulminant form. Certain guidelines for anticoagulation and antiplatelet therapy for thrombosis early should be further established. We present here a case of a patient presented with Comb (+) TTP and developed catheter-associated deep vein thrombosis (DVT). The patient was firstly diagnosed with Evans syndrome. However, he was refractory to a methylprednisolone pulse therapy with a combination of platelet transfusion and eventually developed microangiopathy of central nerve system. The immediate start of PEX (1500ml/d) induced a complete remission of acquired TTP and disappearance of neurological signs and symptoms. However, external iliac and femoro-popliteal venous thrombosis was diagnosed subsequently, inferior vena cava filter (IVC) filter was immediately planting accompanied with anticoagulation therapy. Meanwhile, PEX session was sustained as well as oral anticoagulant (rivaroxaban). 14 days later, the patient got full recovery. Our report aims at raising awareness of Catheter-related DVT under the setting of TTP should be cautious. It is necessary to start anticoagulation and antiplatelet therapy for thrombosis early, especially in such cases when PLT count > 50×109/L.