Paeonia lactiflora Pall. var. trichocarpa is a variety of Paeonia lactiflora Pall., and is currently the peony herb’s principal cultivar group. Here, we study the differences in aromatic components and flowers of different varieties between two groups of cultivars, providing a reference for applying natural fragrance substances of peonies, breeding fragrant flower types, and developing and using improved varieties. Headspace solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS), peak area normalization for each component relative to content, component library (NIST14/NIST14S) retrieval, and a literature review were used to analyze the volatile compounds in flowers of eight peony varieties, such as “Gaoganhong”, and ten comospore peony varieties, such as “Jinshanhong”. Results showed that the main volatile compound constituents in flowers of the two groups were terpenes and alcohols. Additionally, the content of eucalyptol, caryophyllene, α-Pinene, citronellol, and 3-Hexen-1-ol, acetate, (Z) was high. Peony cultivars contained linalool, (1R)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene, and 1,4-dimethoxybenzene, while comospore peony varieties contained 1,3,6-octatriene, 3,7-dimethyl-, (Z)-, phenylethyl alcohol, and geraniol. In this study, the differences between the volatile components of flowers of different peony varieties were clarified, laying a foundation for further molecular biology research into the floral fragrance of peonies and the cultivation of new varieties of aromatic peonies. At the same time, it also provides a theoretical basis for the development and application of peony flower by-products.