Abstract: In order to solve the problem of inference of distortion and electric charge leakage in measuring DC

electric field，a set of experimenting equipment is made based on electrostatic induction theory and varying capacitance

method. Induction DC voltage signal is translated into a certain frequency AC signal. The DC electric-field

strength is measured by electrical technology of amplifying and filtering. The fact that many practical engineering

technology problems are often solved by base physics concepts and laws is demonstrated. The student abilities of integration

of theory with practice are brought up by analyzing the testing theories. The practice abilities and abilities

of analyzing and solving practical problems are improved by designing experimental equipment and experimental research.

The combination of teaching scientific research can satisfy the colligation diathesis of students and students’

consciousness of scientific-research and innovation abilities are improved. This method can be used in practical engineering.

Key words: DC electric field strength, varying capacitance, measuring method