Investigating the diversity of floral organ phenotypic traits in ornamental crabapple cultivars provides theoretical support for targeted breeding, germplasm evaluation, and landscape applications. Seventy-six new crabapple cultivars were studied. Six quantitative floral traits and 14 qualitative floral traits were measured, followed by diversity analysis, correlation analysis, cluster analysis, principal component analysis, and comprehensive evaluation. The Shannon-Wiener diversity of 6 quantitative traits indices between 1.04 and 2.05. A total of 65 variation types were detected across the 14 qualitative traits, with diversity indices ranging from 0.75 to 1.92. Small bud color, large bud color, and outer petal color exhibited higher diversity indices, indicating rich genetic diversity. Correlation analysis revealed high coefficients between quantitative traits, with flowering duration showing a highly significant positive correlation with petal number (r = 0.74). Q-type clustering divided the tested crabapples into four major groups: Group I is suitable for breeding single-petaled, light-colored varieties with strong resistance; Group II is suitable for breeding varieties with large, double flowers and a long blooming period; Group III is suitable for breeding varieties with vivid flower colors; and Group IV is suitable for breeding varieties with a high number of pistils and strong productivity. Principal component analysis transformed 20 floral traits into 7 principal components, cumulatively explaining 78.13% of variance and capturing the most characteristic information of floral phenotypes in ornamental crabapple cultivars. Comprehensive evaluation identified 10 key breeding and ornamental materials with outstanding overall traits, including Malus‘Yi Honglian’, M.‘Zhuang Yuanhong’, M.‘Zi Die'er’, M.‘Chang Hong’. This study provides valuable references for the efficient development and utilization of crabapple resources and for breeding ornamental floral traits.