This work proposes employing a chopping flux modulation technique controlling a high permeability toroid together with a surface acoustic wave (SAW) sensor inside. The experimental results show that the noise floor of this magnetic sensor system is improved. However, the signal-plus-noise-to-noise ratio without the modulation is 17 dB, and with the modulation, this parameter becomes 13 dB for a given mono-frequency signal of 20 µT. In perspective, this method exhibits disadvantages in reducing the sensitivity of the SAW sensor, and further studies are needed to compensate for this loss.