In this paper, Semi-digestion-inductively coupled plasma mass spectrometry method was employed to detect concentration of Ca, Fe, Cu, Pb, Zn, Cd, Mn, Mg and As in rapeseed samples simultaneously. The condition of semi-digestion and inductively coupled plasma mass spectrometry was optimized. Sample pretreatment was compared between semi-digestion and microwave digestion by t-test verification. The results show no significant difference between our method and the microwave digestion method mentioned in GB 5009.268. The relative standard deviation of our method is between 2.5% and 14.5%. The detection limit of 9 elements is between 0.001~0.14 mg/kg. The method has been applied to the determination of nine metal elements in rapeseed samples with satisfactory results.