Aconitum is known for being rich in toxic diterpenoid alkaloids, and many of them are unilateral medicinal materials constituting traditional Chinese medicine, which have important clinical uses. Previous liquid chromatography-mass spectrometry studies were mainly focused on a few common species, but lacked in-depth and detailed research on other species in the same genus, although they have similar or even the same uses. In this study, a comprehensive analysis of the high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry data by semi-quantitative comparisons of the accurate molecular weight and fragmentation pathway of standards was introduced to investigate the diterpenoid alkaloids in four dried root tubers of A. kusnezoffii Reichb., A. carmichaelii Radix., A. pendulum Busch., and A. brachypodum Diels. Thirty-two diterpenoid alkaloids were identified by the molecular networking platform. Their structures were determined by tandem mass spectrometry fragmentation comparisons, and structures that connect fatty acyl groups with different modifications at the C-8 position which in previous studies paid little attention may have better digestion and absorption behavior in drug clinic uses. This work provides a basis for further understanding the clinical efficacy of Aconitum herbs.