A 15.5-W average power,5-kHz repetition rate laser diode(LD) pumped all-solid-state 589 nm yellow laser was reported.Two acoustic-optic Q-switched LD pumped Nd:YAG lasers of 1064 nm and 1319 nm were used as the basic-frequency lasers.The 589 nm yellow laser was generated by extra-cavity sum-frequency generation(SFG).To get high SFG efficiency,the power ratio and pulse widths of 1064 nm and 1319 nm were optimized.Moreover,the electronic delay technology was employed to make the two lasers time-synchronization.When the total power of 1064 nm and 1319 nm was 140 W,the output power of 589 nm laser was 15.5 W at the matching temperature of 43.5 ℃.The conversion efficiency of SFG was about 11.1%.The repetition frequency of the laser was 5 kHz with the pulse width of about 110 ns.