Abstract: Based on the full space transient electromagnetic theory, the uniqueness of apparent resistivity solution was studied with the different transmitter coil sizes and sampling times. The normalized induced electromotive force was calculated using late apparent resistivity, and the difference between the calculation value and the measured value was compared to compensate the normalized induced electromotive force, the all-time apparent resistivity difference compensation algorithm was put forward. Finally, this algorithm under the less iterations number could greatly improve the calculation accuracy with theoretical model calculations of 1,10,100 Ωm resistivity. The measured data processing results showed that this algorithm had a good application effect compared with late half-space calculation method.