The invention relates to a cased hole formation resistivity logging signal conditioning circuit, which is applicable to the measurement field. The cased hole formation resistivity logging signal conditioning circuit is composed of a preamplifier circuit, a two-order low pass active filter circuit, a two-order high pass filter circuit, and an intermediate-stage amplifier circuit. The circuit adoptsa two-order Butterworth filter circuit, the cut-off frequency of the filter is stabilized, the precision and the stability are high, the circuit has a simple structure, the size is small, the workingis stable, the working efficiency is improved, and the anti-interference performance and the reliability are good. The circuit is composed of a servo amplifier circuit, an integral scanning control circuit, a voltage-controlled crystal oscillator circuit, a third harmonic generation circuit and a system power supply circuit. The circuit has a simple structure, the debugging is convenient, the cost is low, fast starting can be realized, and the circuit can quickly return to a locking state after unlocked under interference.