The lower waveguide of 2 μm InGaAsSb/AlGaAsSb laser diode is optimized based on the research of the asymmetric waveguide. With the introduction of dual waveguide, the 2 μm InGaAsSb/AlGaAsSb laser diode has a high output power, a small far field divergence and good single-mode characteristics. The SimLastip simulation of the 2 μm InGaAsSb/AlGaAsSb laser diode with different waveguide structures were established using the related physical model and software design language. And the results indicate that the dual waveguide can almost double the laser power by decreasing the confinement factors of active region from 0.019 2 to 0.011 3 and obtain the good beam quality with small far field vertical divergence angle of 48°. The dual waveguide can favorably improve the performance of 2 μm InGaAsSb/AlGaAsSb laser diode.