The present invention provides a guidewire adjuster and a delivery-system control handle provided with the guidewire adjuster. The guidewire adjuster includes a support mechanism which has a lumen for a guidewire to extend therethrough; and a driving mechanism for driving the guidewire to move back and forth in the lumen. The guidewire adjuster is able to drive the guidewire to move with respect to a sheath of the delivery system. The support mechanism is connected to the control handle of the delivery system and forms a lumen for accommodating the guidewire. A proximal end of the sheath together with the stent can be driven to move upwardly, due to the relative movement between the guidewire and the sheath of the delivery system. Therefore, the position of the stent can be adjusted by advancing the guidewire forward when the stent has been deployed at a lower position than expected.