Scaling exists commonly and its harm is huge. Because of this, design an amplitude-modulating electromagnetic field generator. The drive signal is obtained by amplitude modulation and power amplification. Generate two sine signals by the wien bridge and make the two signals through the MC1496 multiplier, the carrier’s amplitude changes with the modulator’s rule. And the frequency of carrier and modulator could be changed with the adjustment of the Oscillation resistance. Then, make use of D class amplifier TDA8920BTH to enlarge the power of modulated signal. At last, load the drive signal on a ferrite of magnetic coil to gain an electromagnetic field whose strength is modulated. Differ from the ordinary form of winding pipe with wire line, this design is making the magnetic coil close to a pipe. That’s more convenient for installing and removing. Of course, the concrete effect of descaling is needed to test by further experiments.