The present utility model relates to an ultra-low voltage two-stage ring voltage-controlled oscillator applied to a chip circuit. The oscillator includes two-stage delay units. The oscillator includes two delay units that are connected end-to-end, and adjusts a working frequency by adjusting delay time of the delay unit. The delay unit includes PMOS transistors M1, M2, M3, and M4, NMOS transistors M5, M6, M7, and M8, and a load capacitor CL. The two-stage ring voltage-controlled oscillator of the present utility model uses a substrate feed forward bias structure, reduces a threshold voltage of a transistor, reduces a supply voltage, reduces power consumption, has a large tuning range, and is particularly suitable for a system that works at a low supply voltage.