The energy loss occurs when the beam propagates in the macro bend fiber and is radiated to the cladding, causing the frustrated total internal reflection (FTIR), and the radiated energy is affected by the refractive index of the external condition, which can be used for the liquid level measurement. However, the existing sensors are sensitive to the light and ambient interferences, and have poor signal-noise ratio and high cost. Aiming at theses disadvantages, a continuous liquid level sensor with a dual optical fiber twisted macrobend coupling structure is proposed in this paper. The theoretical and experimental analysis shows that the macro bend fiber energy is fed to the sensitive structure and is modulated by the refractive index of the external condition. An experimental platform is set up and the test I carried out. The results show that the terminal power value of the dark field optical fiber is decreased approximately linearly from 0.448 μW to 0.15 μW and the level resolution reaches to 4 dB when the liquid level decreased from 350 mm to 0. Meanwhile, the main factors which can influence the liquid level sensor measurement are analyzed and verified in this paper.Finally, the influencing factors results of were analyzed to verify.