A high power eye-safe optical parametric oscillator driven by the LD end-pumped Nd:YAlO3 laser was demonstrated based on a non-critically phase-matched KTiOAsO 4 crystal. The mode mismatch compensating resonator was adopted for efficient OPO conversion. The maximum output power of 2.3 W at 1562 nm was achieved at the pulse repetition frequency of 20 kHz. The conversion efficiency between the fundamental light and the signal light was up to 62%, which was much higher than other relative reports.