Provided are an ultra-low-field nuclear magnetic resonance device and an ultra-low-field nuclear magnetic resonance measuring method. The method includes applying a first measurement bias magnetic field corresponding to an excitation frequency of a coherent biomagnetic field generated in association with the electrophysiological activity of human body organs, applying a second measurement bias magnetic field having the same direction as the first measurement bias magnetic field and having a different magnitude than the first measurement bias magnetic field, and measuring a magnetic resonance signal generated in the human body by using magnetic field measuring means.
