An interventional medical device delivery system, comprising a loader provided with a loading tube, a delivery sheath, a dilator, a pushing component and a hemostasis valve, wherein: the loading tube or the delivery sheath is provided with a position-limiting locking connector thereon; an appropriate-rotation control mechanism for controlling a tightening degree between a distal end of the loading tube and a proximal end of the delivery sheath is disposed outside the loading tube or the delivery sheath; the proximal end of the delivery sheath and the distal end of the loading tube engage with each other in a sealed manner, and are threadingly fixed to each other by means of the position-limiting locking connector; and the appropriate-rotation control mechanism rotates in one direction to appropriately tighten a thread-connection, and rotates in the opposite direction to release the thread-connection; characterised in that the delivery sheath is provided with a frustum-shaped surface on an inner wall at an end port thereof and the frustum-shaped surface has a diameter that is gradually reduced inwardly from the end port, a minimum diameter of the frustum-shaped surface is consistent with an outer diameter of the loading tube, and an annular stage is disposed at a portion of the frustum-shaped surface with the minimum diameter, the inner diameter at the annular stage is the same as that of the loading tube, such that an end surface of the loading tube abuts against the annular stage, inner walls of the loading tube and the delivery sheath transit smoothly; the appropriate-rotation control mechanism comprises a handwheel, the handwheel is therein provided with a driving connector that is detachably fixed to the position-limiting locking connector, and an appropriate-stopper is arranged between the handwheel and the driving connector; the handwheel drives the driving connector to rotate with a driving force that is less than a force which forces the appropriate-stopper to be deformed to slide out, and the handwheel drives the driving connector to rotate towards a direction by means of the appropriate-stopper; when the driving force by which the handwheel drives the driving connector to rotate during tightening causes that the appropriate-stopper is deformed to slide out, the handwheel independently rotates relative to the driving connector. the loading tube or the delivery sheath is provided with a position-limiting locking connector thereon; an appropriate-rotation control mechanism for controlling a tightening degree between a distal end of the loading tube and a proximal end of the delivery sheath is disposed outside the loading tube or the delivery sheath; the proximal end of the delivery sheath and the distal end of the loading tube engage with each other in a sealed manner, and are threadingly fixed to each other by means of the position-limiting locking connector; and the appropriate-rotation control mechanism rotates in one direction to appropriately tighten a thread-connection, and rotates in the opposite direction to release the thread-connection; characterised in that the delivery sheath is provided with a frustum-shaped surface on an inner wall at an end port thereof and the frustum-shaped surface has a diameter that is gradually reduced inwardly from the end port, a minimum diameter of the frustum-shaped surface is consistent with an outer diameter of the loading tube, and an annular stage is disposed at a portion of the frustum-shaped surface with the minimum diameter, the inner diameter at the annular stage is the same as that of the loading tube, such that an end surface of the loading tube abuts against the annular stage, inner walls of the loading tube and the delivery sheath transit smoothly; the appropriate-rotation control mechanism comprises a handwheel, the handwheel is therein provided with a driving connector that is detachably fixed to the position-limiting locking connector, and an appropriate-stopper is arranged between the handwheel and the driving connector; the handwheel drives the driving connector to rotate with a driving force that is less than a force which forces the appropriate-stopper to be deformed to slide out, and the handwheel drives the driving connector to rotate towards a direction by means of the appropriate-stopper; when the driving force by which the handwheel drives the driving connector to rotate during tightening causes that the appropriate-stopper is deformed to slide out, the handwheel independently rotates relative to the driving connector.