This study was conducted to identify soil cadmium (Cd) removal pathways and their contribution rates during phytoremediation byPennisetum hybridum, as well as to comprehensively assess its phytoremediation potential. Multilayered soil column tests and farmland-simulating lysimeter tests were conducted to investigate the Cd phytoextraction and migration patterns in topsoil and subsoil simultaneously. The aboveground annual yield ofP. hybridumgrown in the lysimeter was 206 ton·ha−1. The total amount of Cd extracted inP. hybridumshoots was 234 g·ha−1, which was similar to that of other typical Cd-hyperaccumulating plants such asSedum alfredii. After the test, the topsoil Cd removal rate was 21.50–35.81%, whereas the extraction efficiency inP. hybridumshoots was only 4.17–8.53%. These findings indicate that extraction by plant shoots is not the most important contributor to the decrease of Cd in the topsoil. The proportion of Cd retained by the root cell wall was approximately 50% of the total Cd in the root. Based on column test results,P. hybridumtreatment led to a significant decrease in soil pH and considerably enhanced Cd migration to subsoil and groundwater.P. hybridumdecreases Cd in the topsoil through multiple pathways and provides a relatively ideal material for phytoremediation of Cd-contaminated acid soils.