An
impact power tool includes a motor, a first planetary gear set, a
clutch having a sun gear, a second planetary gear set, a transmission shaft, an intermediate shaft, an
impact seat and an output shaft. When the
clutch moves to a first position, the transmission shaft engages with a second
planet carrier of the second planetary gear set and the output shaft. The power of the motor is transmitted to the output shaft via the first planetary gear set, the second planetary gear set, and the transmission shaft in low-speed mode. When the
clutch moves to a second position, the transmission shaft disengages from the second
planet carrier and the output shaft. The power of the motor is output to the output shaft via the first planetary gear set, the second planetary gear set, the transmission shaft, the intermediate shaft, and the
impact seat in high-speed-with-impact mode.