The surface passivation of mercury cadmium telluride (MCT) materials is one of the key processes in the preparation of infrared detectors.High-performance MCT devices require stable and reproducible passivation surfaces and interfaces that meet the device performance requirements. Therefore, it is of great significance to explore MCT surface passivation technology. Molecular beam epitaxy (MBE) in-situ passivation and magnetron sputtering passivation techniques of MCT were studied. The results show that the compactness of the in-situ passivation film by MBE is better, the defect holes on the surface of the passivation layer are smaller, the lattice matching between the passivation layer and the MCT is better, and the current-voltage (I-V) characteristics of the device streamer are better than normal passivation by magnetron sputtering.