Abstract: The 1.7 MV tandem accelerator at Peking University has been running for more than 30 years. The accelerator is equipped with a Radio Frequency(RF) charge exchange negative ion source and a cesium sputtering negative ion source, which can produce most of the ions from H to Au. It can accelerate the ions to energies from several hundreds of keV to several MeV. The accelerator is used for ion implantation and irradiation as well as for ion beam analysis, such as Rutherford Backscattering Spectroscopy(RBS) and channeling. Based on the experimental requirements, a high temperature irradiation system was established, with the highest temperature of 950 ℃. In order to achieve more accurate ion implantation, two Faraday cup structures, direct type and indirect type, are designed. The scanning area of the beam is controlled accurately. These designs can not only suppress the secondary electrons, the influence of secondary positive ions is also considered when measuring the beam intensity. The ion implantation experiments of Au ions with different energy on single crystal silicon were carried out. RBS analysis shows that the error between the measured fluence and the expected fluence is within 4%. In addition, the uniformity measurement shows that the relative standard deviation of the implant fluence is 2%.