OIL PUMP CONTROL METHOD FOR DCT

An oil pump control method for a DCT may include estimating line pressure, using a pressure-up model formed from a relationship between an oil pump driving current and a hydraulic pressure; stopping the oil pump when the line pressure estimated from the pressure-up model is equal to or higher than a predetermined upper limit hydraulic pressure; estimating a dropping line pressure from a first pressure-down model for a predetermined first reference time after stopping the oil pump on the basis of the line pressure estimated when the oil pump is stopped as an initial value; forming a second pressure-down model by opening a solenoid valve supplying hydraulic pressure to a non-drive side clutch, and estimating a line pressure from the second pressure-down model, and returning to the pressure-up step when the line pressure reaches predetermined lower limit hydraulic pressure or less.