In this work, a five channel lattice-matched AlInN/GaN heterostructure SBD is presented to improve the DC characteristics based on Silvaco-Atlas software and the simulation results. The influences of the number of channels, the thickness of the barrier layer, the In composition of the barrier layer, and the anode-cathode distance (L ac ) are theoretically investigated. For an Al 0.83 In 0.17 N diode, compared with single channel devices, it offers a reduction of 68% in on-resistance, R ON (from 6.25 to 1.98 Ω•mm), and 28% (from 1.25 to 0.91 V) in forward voltage, V F . The 2DEG sheet density increases significantly as the In composition decreases and the Al composition increases. When the thickness of the barrier layer increases, the confinement effect of the quantum well will strengthen, and the performance of SBD will be optimized. Finally, we demonstrated a five-channel AlInN/GaN heterojunction SBD sample with V F of 0.81 V and R ON of 1.9 Ω•mm which is in high agreement with simulation results and is much better than those conventional AlGaN/GaN heterojunction SBDs with the same device area.