A method for obtaining a cycle of a physiological signal includes: a collection device for collecting a vibration signal of body movements； a processor for obtaining a physiological signal by processing the vibration signal； receiving a physiological signal value and a register value, comparing the physiological signal value with the register value, and reserving one of the physiological signal value and the register value； determining the physiological signal value having a corresponding time duration, reaching a given set time to be an extreme value, wherein the time duration is a time duration of the physiological signal value received is not exceeded； restarting the procedure and determining a next extreme value； obtaining the cycle of the physiological signal by processing the at least one extreme value； and displaying the cycle of the physiological signal in a display device.
