For electrical capacitance tomography system

there are some disadvantages such as weak detected signal

low sensitivity

low signal to noise ratio （SNR） and so on. Based on the analysis of the influence on physi- cal properties from sensor structure parameters

a method of selection and analysis for three-dimensional sensor model are put forward. Based on 6 common models and the analysis of empty-pipeline and full-pipeline electrical capacitance values

in the experiment with the adjustment in the parameters of shield thickness

electrode angle and rotation angle between layers

the differences of electrical capacitance values are analyzed

and the curve of ca- pacitance value is plotted along with the parameters. In this method a set of parameters for three dimensional ECT sensor are computed as follows： the referent value scope of shield thickness is between 8 ~ 12 mm

the referent val- ue scope of electrode angle is between 50 ~ 54°

and the referent value of rotation angle between layers is 45°

which supplies a novel idea for the design of three dimensional ECT sensor.