Recently, the spectroscopy technology has advanced extremely rapidly. It can utilize the characteristics of light absorption, reflection, and transmission of materials to perform the qualitative and quantitative analysis of materials. It is a fast, nondestructive detection technology widely used in the testing of agricultural products. Walnut is an important agricultural product with rich nutritional value and long cultivation history in my country. Many scholars have conducted long-term and in-depth research on walnut. This review summarizes the research progress on hyperspectral and infrared spectroscopy with respect to walnut detection from four aspects: variety identification, growth monitoring, quality identification, and sorting and processing. Furthermore, this review compares and analyzes the advantages and disadvantages of various spectral detection technologies and proposes existing problems in walnut correlation detection. The development prospect of walnut nondestructive testing is prospected.