We propose a method to acquire respiration and heartbeat signals based on FBG sensors. A combined variational mode decomposition with improved wavelet threshold function (VMD-IWT) noise reduction algorithm is used to remove noise interference existing in signals. The simulation results show that our proposed algorithm realizes the best SNR, RMSE, and other indicators, and makes actual signals smoother after noise reduction. We use a band-pass filter to separate signals and calculate their frequencies. The maximum error rate of heart rate is 8.75% with respect to the reference value, and the maximum deviation of respiration rate from the reference value is 1 bpm, which proves the better accuracy of the proposed method. This provides a more convenient and economical way to monitor health at home.