1. A sweep-type fingerprint sensor module, comprising: a microprocessor; and a sweep-type fingerprint sensor, which is electrically connected to the microprocessor and comprises: a substrate; a sensing members array formed on the substrate and composed of a plurality of fingerprint sensing members arranged in a two-dimensional array, the sensing members array sensing a fingerprint when a finger sweeps across the sensing members array, sequentially acquiring a plurality of fingerprint fragment images of the finger with a sampling time interval, and outputting a plurality of fingerprint fragment signals corresponding to the fingerprint fragment images accordingly; a speed-detecting unit formed on the substrate and composed of a first plate electrode and a second plate electrode, the first and second plate electrodes being substantially parallel to each other and spaced apart by a predetermined distance, the first plate electrode outputting a first time signal when it contacts the finger, and the second plate electrode outputting a second time signal when it contacts the finger; and a processing circuit electrically connected to the sensing members array and the speed-detecting unit to receive, process and then output the plurality of fingerprint fragment signals, the first time signal, and the second time signal, wherein the microprocessor derives a sweeping speed of the finger according to the first time signal, the second time signal, and the predetermined distance, determines the sampling time interval according to the sweeping speed, and re-constructs the plurality of fingerprint fragment signals into a complete fingerprint image.