The present invention discloses a pulse lie detection method and apparatus based on linear frequency modulation, the sensor adopts a non-array ultrasonic probe to transmit a continuous signal of linear frequency modulation, the linear frequency modulation signal has the advantages of being accurate, anti-multipath and de-aliasing. Combined with predistortion processing, pulse compression, and hierarchical echo inversion algorithm, through the time delay between each reflected echo, the position (depth) of each reflecting surface is obtained; using the attenuation function of the ultrasonic wave in the body, the amplitude of the transmitted signal and the echo signal in each reflection layer is inversely deduced by iteration, and the reflection coefficient of each layer of the reflecting surface is calculated; the reflection coefficient can determine the tissue composition of each reflection layer, and obtain the depth, frequency, amplitude and other multi-dimensional pulse information of the pulse, so as to provide more dimensional reference for the judgment of the lie detection result.
