In this study, SRIM software based on the Monte Carlo method is used to simulate the defect behavior in Ge during He ion implantation, which provides theoretical guidance for the preparation of high-quality GOI (Ge on insulator) materials. The effect of the implantation angle, energy, and dose of the He ion on the damage degree and sputtering yield in Ge material was investigated. The results show that, the training effect is not serious when the incident angle is low. The channel effect can be avoided and the DPA in Ge material can be decreased. With the increase of the energy, the project range increases and the sputtering yield decreases. Moreover, the DPA in the Ge near surface decreases with the increase of the energy, indicating the low DPA in the GOI(Germanium-on-Insulator, GOI) material. The increase of ion implantation dose leads to the increase of the damage area and the aggregation of the defects. Moreover, when the dose increases, more He ions aggregate near the project range. This may lead to the decrease of the lift-off temperature of GOI material.