Based on the different deformations of optical fibers under different bending curvatures, a novel optical fiber curvature sensor is proposed and demonstrated based on seven-core fiber (SCF) and few-mode fiber (FMF). In the experiment, three kinds of sensors with different structures are prepared, and their interference modes are analyzed with the fast Fourier transform (FFT) method. The sensing sensitivities of wavelength are 6.33, 30.83, 15.96 nm/m, respectively, while the sensing sensitivities of intensity are 8.57, 25.65, 1.96 dB/m, respectively.