A quasi-continuous wave (QCW) microsecond-pulse sodium beacon laser with high power, high beam quality and narrow linewidth is achieved by sum-frequency generation (SFG) with Nd:YAG 1064 and 1319 nm lasers in a nonlinear crystal of LBO. Under repetition rate of 500 Hz and pulse width of 120 μs, the 589 nm yellow laser which can be precisely tuned to sodium D2 line is obtained with average output power of 33 W, beam quality of M2 = 1.25, linewidth less than 0.4 GHz and wavelength stability better than ±0.3 GHz. Compared with continuous wave (CW) sodium beacon laser, QCW microsecond-pulse sodium beacon laser named as the second-generation sodium beacon laser can provide a gatable pulse format to eliminate the interference of atmospheric Rayleigh scattering and reduce stretching phenomenon of the imaging spot for sodium guide star. By the combination of the QCW laser sodium beacon and the adaptive optics system, the better correction effect and higher-resolution observation images can be achieved. A second-generation sodium beacon laser prototype is developed and the sodium laser guide star is generated and imaged by the 1.8 m telescope in Yunnan Province.