The invention provides an inductively coupled plasma mass spectrometry and a collision/reaction cell thereof. The collision/reaction cell comprises a chamber and an ion guiding device in the cell body. The cell body is provided with an ion inlet, an ion outlet and a gas inlet. The ion outlet is deviated from an advancing path of the ion in entering the chamber from the icon inlet. The ion guiding device forms a bent ion channel which is used for guiding the ions to move from the ion inlet to the ion outlet. The bent ion channel is provided with two bending guiding parts which can guide the ions to be bent in a reverse direction. The collision/reaction cell is characterized in that the chamber is internally provided with the ion guiding device and furthermore the ion guiding device isi provided with two bending guiding parts, and therefore the advancing direction of the ions in leaving the chamber from the ion outlet is approximately parallel with the advancing path of the ions in entering the chamber from the ion inlet; and furthermore interferences of multi-atom ions, neutral molecules and photons can be eliminated.