A continuous-wave π-polarized 1084 nm laser based on Nd:MgO:LiNbO3 crystal is reported under 888 nm double-end pumping with low quantum defect. When the absorbed pump power is 28 W, the π-polarized 1084 nm laser achieves a maximum output power of 8.73 W and a conversion efficiency of 31.1% under double-end thermally boosted pumping. The beam quality factor M2 is 1.61 and 1.68 in the x and y directions, respectively. Compared with the single-end pumping, the output power of the double-end pumping is increased by 3.33W, and the conversion efficiency is increased by 5.4%. The experimental results show that double-end thermally boosted pumping can handle higher injection power, resulting in a higher output power of π-polarized 1084 nm laser.