Abstract: With the problem of large power consumption of current reference and narrow supply voltage range, a CMOS reference current source with low power consumption, wide voltage range and low temperature coefficient is proposed.The reference current is generated by adding a certain proportional coefficient between the PTAT and the CTAT current, exhibiting temperature-independent characteristics. Based on CMOS sub-threshold op amps and self-cascading current mirror, it expands the supply voltage range, reduces overall circuit power consumption, and improves circuit performance. The circuit is designed based on the XFAB 0.35 μm CMOS process. The result show that the reference current is 5 μA, the temperature drift coefficient is 40ppm/℃ in the temperature range of -25℃~125℃, the power supply voltage is 2.5 V~6 V, and the power consumption is 25 μA.