Abstract: Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the content of cadmium (Cd) and arsenic (As) in earthworms. A physiologically-based extraction test (PBET) digestion in vitro/MDCK cell model was established to investigate the bioaccessibility of Cd and As in earthworms. The hazard index (HI) method and the margin of exposure (MOE) method were used to assess the risks of the total content and the bioaccessible content of Cd and As. The results showed that the total content of Cd and As in six batches of earthworms ranged from 8.319 to 33.606 mg·kg^-1 and from 0.532 to 16.412 mg·kg^-1, respectively. After uptake by MDCK cells, the bioaccessibility of Cd in earthworms ranged from 10.13% to 64.16%, and the bioaccessibility of As was from 2.72% to 46.57%. The results of risk assessment showed that before uptake by MDCK cells, the MOE values of As and HI values of Cd for all batches of earthworms were greater than 1, which suggests that the risks of As are acceptable but the risks of Cd are unacceptable. After transportation by MDCK cells, except for one batch of earthworms, the HI values of Cd in the other five batches were less than 1, which suggests that the risks are at a safe level. This study provides important technical support for a more objective and scientific assessment of the health risks of heavy metals in traditional Chinese medicines, and for a more scientific and reasonable standard limit of heavy metals.