The application prospect and production methods of the high-repetition-rate, high average power 2 μm laser were reported. With the KTP crystal refractive index ellipse and the Sellmeier equations, the tuning characteristic of the crystal about the cutting angle was analyzed when the 1.064 μm continuous Nd:YAG laser pumped the type Ⅱ phase matching KTP crystal. The cutting angle tuning curve was also calculated. As a result, when the cutting angle was 52.6°, the signal and the idler were degenerated at 2.128 μm with perpendicular polarization. To restrain the dispersion effect, the authors combined the intracavity optical parametric oscillator (OPO) with the short crystals connecting external OPO and designed an experimental set of intracavity doubly resonant optical parametric oscillator with two short KTP crystals connecting, with which high-repetition-rate 2 μm laser output was readized with acoustic-optic Q-switch. Finally, the threshold, the converting efficiency, the crystal dispersion length and the linewidth were numerically simulated.