Abstract: In response to the issue of poor accuracy in traditional bandgap reference circuits, a low-drift bandgap voltage source with a high-order compensation structure is designed. Building on a first-order bandgap reference, higher-order temperature compensation terms from the gate-source voltage of sub-threshold MOSFETs biased under PTAT current are used to offset the higher-order temperature terms in the transistor′s emitter junction voltage, resulting in a bandgap reference with an extremely low temperature drift coefficient. The reference is designed using a 0.35 μm BCD process, with a layout area of 345 μm × 140 μm. Simulation results show that the temperature drift coefficient of the reference is only 1.9 ppm/℃ over a supply voltage of 5 V and a temperature range of −55 ℃ to 125 ℃, with a power consumption of 22.3 μW at 25℃ and a PSRR of −70.68 dB at 1 kHz.