We have made a gain-switched all-solid-state quasi-continuous-wave (QCW) tunable Ti:sapphire laser system, which is pumped by a 532nm intracavity frequency-doubled Nd:YAG laser. Based on the theory of gain-switching and the study on the influencing factors of the output pulse width, an effective method for obtaining high power and narrow pulse width output is proposed. Through deliberately designing the pump source and the resonator of the Ti:sapphire laser, when the repetition rate is 6kHz and the length of the cavity is 220mm, at an incident pump power of 22W, the tunable Ti:sapphire laser from 700 to 950nm can be achieved. It has a maximum average output power of 5.6W at 800nm and the pulse width of 13.2ns, giving an optical conversion effciency of 25.5% from the 532nm pump laser to the Ti:sapphire laser. We have made a gain-switched all-solid-state quasi-continuous-wave (QCW) tunable Ti: sapphire laser system, which is pumped by a 532 nm intracavity frequency-doubled Nd: YAG laser. Based on the theory of gain- switching and the study on the influencing factors of the output pulse width, an effective method for obtaining high power and narrow pulse width output is proposed. and the length of the cavity is 220mm, at an incident pump power of 22W, the tunable Ti: sapphire laser from 700 to 950nm can be achieved. It has a maximum average output power of 5.6W at 800nm ​​and the pulse width of 13.2ns , giving an optical conversion effciency of 25.5% from the 532 nm pump laser to the Ti: sapphire laser.