The invention discloses a numerically controlled ring oscillator and a control method and device thereof. The numerically controlled ring oscillator comprises a high-order numerically controlled oscillator; and a low-order numerically controlled oscillator of which the input end is connected with the output end of the high-order numerically controlled oscillator and the output end is connected with the input end of the high-order numerically controlled oscillator and the output end of the numerically controlled ring oscillator, wherein the control code of the high-order numerically controlled oscillator is a high-order control code, and the control code of the low-order numerically controlled oscillator is a low-order control code. The technical problems of limitation of the output frequency accuracy and the output frequency range of the numerically controlled ring oscillator in the prior art can be solved.