A temperature-independent curvature sensor was presented for solving the high cost of wavelength demodulation and cross sensitive problem. The sensor consists of a fiber Bragg grating spliced after a peanut-shaped fiber, and it is reflected light intensity demodulation. With the broadband light entering the peanut-shaped structure, the cladding mode is excited, being reflected by the FBG, the reflected core mode is excited by the peanut-shape structure again making several ranking cladding modes, which interference with the core mode. The reflected spectrums not only consist of the FBG peak but also consist of several resonant peaks, the shorter the wavelength is, the higher ranking of the cladding mode is. The experiment results show that the intensity of the reflected resonant peaks decreases from 2.260×10－7 mW to 1.501×10－7 mW with the curvature increases from 0.669 0 m－1 to 1.250 0 m－1. The average curvature sensitivity is －1.306×10－7 mW/ m－1. Temperature test on the structure shows that the power of the reflected cladding modes made little change with temperature increases from 25℃ to 75℃. The proposed curvature sensors is less expensive and the peanut-shaped structure has the feature of easy making and high mechanical strength etc.