The invention discloses a target detecting and identifying method and a target detecting and identifying system based on a sound vibration signal. The method comprises the steps of acquiring a vibration signal at a preset node position in a preset time period and storing the vibration signal into a vibration data matrix by means of M fiber sensors or equivalent M fiber sensors; performing preprocessing on the vibration data matrix by means of a pre-emphasis method, and selecting a bipolar data frame which comprises a target signal; extracting a speed characteristic, an energy distribution characteristic and a spectrum estimation characteristic of each row of each kind of signal from the bipolar data frame, acquiring a relatively long characteristic vector matrix according to each characteristic and a corresponding weighted value and performing dimension reduction on the relatively long characteristic vector matrix; and identifying the vibration signal kind of the bipolar signal data, the bipolar signal data frame and the relatively long characteristic vector after dimension reduction by means of a long-and-short-period selection memory neural network model. According to the target detecting and identifying method and the target detecting and identifying system, sound vibration signal identification is determined according to combined action of information in different steps, thereby improving target identification accuracy.