In this paper, we demonstrate the high power diode-side-pumped Nd:YAG laser on the low gain three lines at 1112, 1116 and 1123 nm. By special coating design or inserting etalon in the cavity, the single wavelength oscillation can be achieved with high output power either in continuous-wave (CW) mode or in actively Q-switched (QS) mode. With special coating design, the maximum CW output power at 1123 nm can be up to 219.3 W. By tuning the tilt angle of an etalon in the cavity, the highest output powers at 1112, 1116 and 1123 nm were obtained to be 72, 43 and 63 W operated in QS mode, and 75, 47 and 71W in CW mode, respectively. This compact laser system, which is capable of selectively operation at one of the three lines at 1112, 1116 and 1123 nm, is of important practical value. The high power achievable with the present laser may enable some interesting applications, such as chemistry, differential absorption lidar, second harmonic generation (SHG) into visible and fourth harmonic generation (FHG) into ultraviolet lasers.