The invention relates to a voltage reference source circuit with low power consumption and a low temperature coefficient. The voltage reference source circuit is characterized by comprising a PTAT current generating circuit and a load circuit, wherein the PTAT current generating circuit is connected with one end of the load circuit; the reference voltage source is output from the load circuit; the PTAT current generating circuit consists of PM0, PM1, PM2, PM3, NM0, NM1, NM2, NM5 and NM6; the PM0, the PM1, the PM2 and the PM3 are PMOS (P-channel metal oxide semiconductor) tubes; the NM0, the NM1, the NM2, the NM5 and the NM6 are NMOS (N-channel metal oxide semiconductor) tubes. Compared with the prior art, the voltage reference source circuit has the advantage that the voltage reference source circuit can normally work at low voltage, or even ultra-low voltage.