There is always a contradiction between the heat-sinking capability and the volume in the engineering applications of the micro-diode-pumped solid-state laser (DPL). Using of narrow pumping width technology not only improves the products in the quality of photoelectric technology, but also decreases the heat output in key parts of apparatus to 30% of original level. It effectively solves the problem which is the heat output of the tiny parts of apparatus and improves the overall performance of the laser. Under the conditions of repeat frequency 2.5 kHz and pumping duration 120 μs, it achieves the peak power of 12.1 kW, impulse width of 7.7 ns and the laser beam quality factor M2 1.7 in pulse output while the laser works stably from -55 ℃ to ＋75 ℃. The technology greatly improves the developable space for equipment system. Clients could increase the repeat frequency to 5 kHz or even higher if needed.