Failure modes during screening tests and application processes have been summed up for HgCdTe linear photoconductive detectors which have been applied in several programs. The mechanisms behand these failure modes have been analyzed based on the combination of HgCdTe material parameters, device structure dimensions, detector physics, fabrication processes and device test techniques. Criteria of failure modes have been firstly proposed for deeper understanding of HgCdTe linear photoconductive detector and better optimization of detector screening process, which are also helpful for the analysis and resolution of problems encountered in the application of HgCdTe linear photoconductive detectors.