A laser diode (LD) pumped, narrow-pulse-width, high-power solid-state laser was designed using a master oscillator power amplifier (MOPA) configuration. The master oscillator stage utilizes a neodymium-doped yttrium orthovanadate (Nd:YVO₄) crystal as the laser gain medium in combination with a rubidium titanyl phosphate (RTP) electro-optic Q-switch. The pulse width characteristics at high repetition rates were analyzed, yielding narrow pulse width output from the master oscillator stage. The power amplifier stage employes a configuration that features LD dual-end pumping of the Nd:YVO₄ crystal. A three-dimensional thermal simulation model was established to comparatively analyze the thermal effects in the gain medium under LD single-end and dual-end pumping. The influence of LD pump spot size and gain medium length on thermal effects in the power amplifier stage under dual-end pumping was investigated. Following experimental optimization of the laser parameters, the MOPA system achieved a maximum average power of 22.01 W with a pulse width of 4.33 ns at a wavelength of 1 064 nm and a repetition frequency of 10 kHz. The corresponding optical-to-optical conversion efficiency was 18.21%.