A diode-pumped solid-state laser at 1.5 μm by use of the Er3+,Yb3+YAl3(BO3)4 crystal is presented. Initially, the laser efficiency is quite low and can not be operated continuously owing to the serious thermal effect. To solve these problems, the oven design and pumping source parameters including operation frequency, duty cycle and waist radius are optimized for reducing the crystal′s thermal deposition. A more efficient quasi continuous-wave (CW) laser which can produce output power of 2.6 W at 1.5 μm is realized when the pumping source is set as modulated frequency of 40 Hz, duty cycle of 10%, pumping waist radius of 80 μm and incident power of 17.6 W. Furthermore, a CW single-transverse-mode laser with output power of 290 mW and slope efficiency of 8.5% is also demonstrated under pumping power of 5 W.