Accelerator mass spectrometry (AMS) is one of the most promising methods to detect minute amounts of 182Hf. However, the sensitivity of 5×10-11 for 182Hf/180 Hf obtained previously by the AMS method at China Institute of Atomic Energy (CIAE) cannot meet the requirement of some applications. We present some new improvements of measurement method for AMS measurement of 182Hf at the CIAE HI-13 tandem accelerator system. As a result, a sensitivity of 1.0×10-11 for 182Hf/180Hf is achieved.