By implementing astigmatism compensation of the laser resonator,selecting stable operation conditions as well as optimizing the mode match between light fields and tuning elements,we design and build a stable single-frequency continuous-wave (CW) all-solid-state Ti:sapphire laser with short cavity length. The pump source is a homemade CW single-frequency green laser. Under the pump power of 4 W,the output power of 670 mW at the wavelength of 780 nm is obtained. The intensity fluctuation of the output laser is less than ±0.4% during 1 h,and the beam quality factor M2<1.1. After the laser resonator is locked on a confocal reference cavity with an electronic servo-system,the frequency stabilities are better than ±188 kHz and ±3.28 MHz over 10 s and 15 min respectively in the totally tunable range from 750 nm to 810 nm.