This paper introduces the basic working principle of capacitive micromachined gyroscope. A novel differential lengthwise capacitance comb detection structure is put forward. And it also analyzes the linearity of the differential lengthwise capacitive comb detection structure compares to the transversal detection. By measuring the scale factor, it verifies the high linearity of lengthwise differential capacitive detection structure. The linearity insures the linearity of conversing section of the detect system’s displacement and the capacitive variation. And this will greatly improve the linearity and stability of micromachined gyroscope.