To explore the genetic diversity of key agronomic traits among the existing sugar beet germplasm resource materials and the foreign introduced resource materials, genetic diversity analysis, principal component analysis and phenotypic clustering analysis of 12 agronomic traits of 679 domestic and foreign sugar beet germplasm resource materials were conducted in this study. The results showed that the nine identified descriptive agronomic traits had genetic diversity indices ranging from 0.5876 to 1.4250 with a mean of 1.0058. The materials with the highest magnitude of numerical variation for tuber yield and sucrose content among the three numerical agronomic traits were all from Inner Mongolia, China, the material with the highest coefficient of variation for yield was an introduced material from the Netherlands, and the material with the highest coefficient of variation for sucrose content was from France. The highest coefficient of variation and magnitude of variation in sugar yield was found in the introduced material from Lane, UK. The results of cluster analysis showed that 679 materials could be divided into four categories, and 99.13% of the materials from Inner Mongolia could be divided into one category, indicating that in terms of introducing foreign species, the purpose is clear, and the introduction of different kinds of foreign materials can also make the phenotypic resource base more complete.