The experimental results of a high-efficiency infrared-laser are demonstrated on a quasi-phase-matched (QPM) single-resonated optical parametric oscillator (OPO) in PPMgLN (5% MgO-doping) pumped by a 1064 nm laser of an elliptical beam. Theoretical analyses of the PPMgLN temperature tuning are presented. The pump source was an acousto-optically Q-switched continuous wave (CW)-diode-side-pumped Nd∶YAG laser,the pump beam polarization matches the e→e+e interaction in PPMgLN,thus maximal nonlinear coefficient d33 (27.4 pm/V) is effective and walk-off of beams can be avoided. When the pump power was 104 W with a repetition rate of 7 kHz and PPMgLN crystal temperature of 110 ℃,an average output power of 62.7 W was obtained with a slope efficiency of 71.7%,with 16.7 W at the mid-infrared wavelength of 3.84 μm and 46 W at the near-infrared wavelength of 1.47 μm.