The utility model relates to a puncture trocar for inferior vena cava, which is used for saccule dilation forming therapy and inner support implantation therapy of velar locking or periodic locking of the inferior vena cave at a proximal part. The utility model is composed of a needle core and a cannula. The needle core is sheathed in the cannula. The needle core is a steel wire provided with a certain size. The head end of the needle core is roundish and blunt. The position near the head end is arced bent. Partial of the tail end is inflated, and the tail end is provided with an arrowhead type structure. The cannula is a pointed-end plastic straight catheter. The utility model has the advantages of safety, accuracy and convenience when the utility model is used for puncturing the inferior vena cave.