Abstract: Recently, increasing interest in mass spectrometry is focused on miniature instrumentation, especially on the development of miniature ion trap mass spectrometer. The motion of the ions can be expressed by Mathieu Equation and its stability diagram. The mass spectrum of the analyzed ions can be achieved by scanning the amplitude of the RF voltage. The miniaturization of the ion trap mass spectrometer mainly focuses on the miniaturization of components, including ion fountain, mass analyzer, ion detector and vacuum system.With the development of science and technology, the main studies focus on miniaturization, wider applications, higher resolution and wider mass range, rapid analyzing and lower cost.