InSb infrared focal plane array (IRFPA) detectors are playing important roles in the medium wave infrared band. But cross-shaped dead pixels severely reduce the performance of the detectors. It was found that indium bumps were invalid in the cross-shaped dead pixels′ regions by focused ion beam technology. Further inspection revealed that the indium bump preparation parameters were not good. Through improving the shape of the indium bumps and increasing the height, the firmness of the welding surface was strengthened, very few InSb detectors had the problem of cross-shaped dead pixels. The optimized InSb infrared detectors were baked at 80 ℃ for 14 days, and the number of cross-shaped dead pixels remained unchanged after testing. The reliability of indium bumps was good. Optimizing indium bump preparation technology can effectively solve the cross-shaped dead pixels problem. Interconnection failure is the main cause of the cross-shaped dead pixels problem. By analogy, this method can solve the cross-shaped dead pixels problem of all InSb infrared detectors.