Abstract: This paper proposes a high isolation CMOS analog switch circuit design aimed at ameliorating the limited isolation of traditional analog switches and the long switching time of mechanical reed switches. This high isolation analog switch is applied to a high-precision digital sampling impedance bridge, addressing issues of slow signal switching speed in bridge systems and signal leakage affecting the accuracy of vector voltage ratios. The proposed analog switch design simplifies the digital bridge system, providing superior off-isolation and switching speed across a broad frequency range compared to traditional analog switches. This ensures the high-precision traceability of impedance measurements using the digital sampling method while increasing the speed of impedance calibration, hence improving practicality. A high-precision dual-stage voltage follower circuit is also utilized to mitigate the impact of the on-resistance of the analog switch on the bridge circuit. Experimental results validate the proposed design, achieving an off-isolation better than -140 dB at 1 kHz and enabling rapid, high-precision impedance parameter measurements in the frequency range of 100 Hz to 100 kHz.