This study utilized ultra-high-performance liquid chromatography coupled with quadrupole-electrostatic field orbitrap high-resolution tandem mass spectrometry (UPLC-QE Orbitrap MS/MS) to identify the chemical components in Alocasiae Cucullatae Rhizoma aqueous extract (ACRAE) and rat serum. Chromatographic separation was performed using a gradient elution with a mobile phase of water (containing 0.1% formic acid) and acetonitrile at a flow rate of 0.35 mL/min, with an injection volume of 5 μL. Mass spectrometric analysis was carried out with a heated electrospray ionization (HESI) source, and data were acquired in both positive and negative ion modes over a scanning range of m/z 100–1 200. By comparing the chromatographic profiles of ACRAE, blank serum, and drug-containing serum, prototype components and metabolites in the serum after oral administration were identified based on retention times, molecular weights, and both primary and secondary ion fragments. A total of 135 chemical components were characterized in the ACRAE. In serum, 68 blood-absorbed components were detected, including 23 prototype components and 45 metabolites. The rapid profiling of blood-absorbed components in ACRAE via UPLC-QE Orbitrap MS/MS provides critical insights for further exploration of its pharmacodynamic material basis and mechanisms of action.