A shift control method in a vehicle having a dual clutch transmission may include determining whether power-off downshifting is being carried out, monitoring whether a tip-in is caused by a driver during the power-off downshifting, releasing all of a transmission torque of a releasing clutch and a transmission torque of a coupling clutch if it is determined that the tip-in is caused during the power-off downshifting, decreasing an engine torque at a point of time when an engine speed becomes identical to a speed of a coupling input shaft on which a target gear is disposed, and synchronously increasing the engine torque by gradually increasing the transmission torque of the coupling clutch and gradually reducing an amount by which the engine torque is decreased when the releasing clutch has completed a releasing action and the engine speed becomes faster than the speed of the coupling input shaft.