Gear shift control method of DCT vehicle

A gear shift control method of a Dual Clutch Transmission (DCT) vehicle, the method comprising:

• a gear shift start determination step of determining whether a kick down shift, which performs a gear shift to a lower gear as an acceleration pedal is handled according to an acceleration intention of a driver, is started;
• a biaxial shift determination step of determining, when the kick down shift is started, whether the gear shift is a biaxial shift, in which a difference of gear level between a target gear and a current gear is as much as an odd-numbered gear level larger than one level;
• a clutch torque control step of uniformly decreasing torque of a release-side clutch and uniformly increasing torque of a connection-side clutch to synchronize revolutions per minute of a target gear input shaft with increasing revolutions per minute of an engine, when a current gear state of the vehicle determined at the biaxial shift determination step is the biaxial shift;
• a clutch synchronization determination step of determining whether the revolutions per minute of the target gear input shaft is synchronized with the revolutions per minute of the engine by the clutch torque control;
• and
• a gear shift performing step of performing gear shift control for engaging the target gear, when the revolutions per minute of the target gear input shaft is synchronized with the revolutions per minute of the engine.