The invention discloses a measuring method of finger tip blood flow rate based on an accelerated pulse wave and a measuring instrument thereof. The instrument comprises a volume pulse wave acquisition module, a signal conditioning module, an operation processing module, an external mass memory module, a USB (Universal Serial Bus) communication module, a waveform and result display module. The measuring method comprises the following steps: during measuring, detecting a human finger tip pulse beating signal a volume pulse wave sensor, after passing through the signal conditioning module, converting the human finger tip pulse beating signal into a digital signal by using operation processing module, storing the digital signal in the external mass memory module, carrying out twice differential processing and filtering processing on a volume pulse wave so as to obtain a smoothing quadratic differential waveform, namely an accelerated pulse wave required by a system; extracting out pulse wave propagation time from the accelerated pulse wave, and establishing a functional relation between the propagation time and human blood pressure so as to determine blood flow rate. The measuring method of the finger tip blood flow rate based on the accelerated pulse wave and the measuring instrument thereof realize non-invasive, convenient and fast, accurate and reliable measurement on the finger tip blood flow rate; the measuring instrument requires few input signals; and the relation between a input signal and a measuring result is stable.