A novel all fiber short linear-cavity Q-switched Erbium doped fiber (EDF) laser with a compact short carbon nanotube based saturable absorber (CNT-SA) is presented. The fiber laser cavity is only 10.5cm. It is constructed by connecting a 6.5-cm high concentration EDF and the CNT-SA in a linear-cavity formed by two fiber Bragg gratings. With the short cavity, no self-mode-locking effect on the Q-switch operation occurs. Moreover, higher pulse-repetition-rate and shorter pulse duration are not only achieved but also the stability of the laser cavity is improved.