Metal halide perovskites, which have aroused the enormous interest from scientists recently, are widely used in a variety of areas such as solar cells, light emitting diodes (LED) and lasers. Nanomaterials exhibit distinguished optical and electrical properties because of their quantum confinement as well as strong anisotropy. The metal halide perovskite nanomaterials have the advantages of adjustable band gap, high quantum efficiency, strong photoluminescence, quantum confinement and long carrier-lifetime. Besides, as a result of the low-cost fabrication and the sufficient raw material reserve, they have a broad prospect in photoelectric applications. But on the other hand, the poor stability of metal halide perovskites, due to the defect trap states and grain boundaries on the surface, cast a shadow towards their practical applications. The moisture, oxygen and ultraviolet of the environment will degrade their photoelectric performances significantly. In this review, we introduce the synthesis and growth mechanism of metal perovskite nanomaterial quantum dots, nanowires and nanoplatelets, and present their novel photoelectric properties and applications in various photoelectric devices. Finally we summarize the emerging challenges and discuss the next-generation photoelectric applications.