The present invention discloses a catheter system, comprising: a catheter head having a lumen, a proximal end and a distal end, and an opening positioned at a bottom of the distal end； and a rotatable inner tube having a lumen positioned in the lumen and at a proximal end of the catheter head, the inner tube including a front end having an arcuate opening； wherein the rotatable inner tube can be rotated so that the arcuate opening thereon can be made to engage or disengage with the opening at the bottom of the distal end of the catheter head. The invention also provides a catheter system and method for re-entry of a vascular false lumen into a true lumen in a quick, accurate and low-risk way. The catheter system for re-entry of a vascular false lumen into a true lumen in a quick, accurate and low-risk way effectively solve the problems of difficult operation, inaccurate positioning, long operation time and easiness to cause acute occlusion and internal hemorrhage of the branch vessel when the guidewire is re-entering the true lumen in the prior art.
