To obtain the dark current mechanism of In0.83Ga0.17As detector, TCAD software was used to simulate its dark current property. The detectors include two structures with and without the super lattice (SL) electronic barrier in the InGaAs absorbed layer. At the same time, the detector has been fabricated to verify the simulation results. The results show that SL barrier can adjust the energy band structure and change the transport property of the carriers, and thus suppress the SRH recombination and decrease the dark current. Simulation results are in good agreement with experimental results. The influence of the location and periods of SL barrier on dark current was also simulated. The SL electronic barrier structure was optimized.