In the case of a large thrombus in the superficial veins of the lower extremities, it is necessary to put a filter, but if the thrombus is small, you can not need to put a filter. If the thrombus is small, you don’t need to put a filter. If the thrombus is big, the thrombus in the superficial vein of the lower limb may be dislodged, and the dislodged thrombus will flow into the pulmonary artery with the blood from the vein, which can cause fatal pulmonary infarction. In this case, shallow vein thrombosis of the lower limbs is necessary to put a filter to block the dislodged venous thrombus upward, which can effectively avoid the occurrence of pulmonary embolism. Lower extremity superficial vein thrombosis is small, usually will not fall off, will not cause pulmonary infarction, life will not cause corresponding impact, this case of lower extremity superficial vein thrombosis can not need to put the filter. If the patient has lower extremity superficial vein thrombosis, it is recommended that the patient go to the hospital in time, after a clear examination, follow the doctor’s instructions for treatment.