The logging-while-drilling ARC675 system by Schlumberger is taken as example in the analysis of the influencing law of dielectric effect on relative bit shift and amplitude fading electric resistivity.The correcting charts and the methods of ARC 675 logging-while-drilling tool under the condition of 2MHz and 400KHz are given out,the automatic dielectric effect computer program is developed and the dielectric effect correcting for in-situ logging-while-drilling data is carried out,the result verifies the analysis of the influencing factors on dielectric effect,more precise formation resistivity value is obtained.Case study indicates the matching equation is correct.