The invention relates to a CFRP porosity ultrasonic characterization method based on ultrasonic backscattered signal recurrence quantification analysis, and belongs to the technical field of nondestructive detection. The method comprises the steps that an ultrasonic signal collecting system composed of an ultrasonic flaw detector, a delay block probe and a digital oscilloscope is adopted, an ultrasonic backscattered signal is collected, and phase-space reconstruction is conducted on the ultrasonic backscattered signal. Distance between every two time vectors in a phase space is calculated, a reference threshold value is set, a two-dimensional recursive matrix is obtained, and the two-dimensional recursive matrix is visualized to obtain a Recurrence Plot (RP). An RP graph is subjected to quantitative calculation through RQA quantitative index Recurrence Rate (RR), the correlation between the CFRP porosity P and RR is established finally, RR=aP-1, and characterization of the porosity is achieved. Compared with an ultrasonic attenuation method, the limitation that when a bottom echo does not exist or is weak, the porosity cannot be characterized is overcome through the method, and a good popularization prospect is achieved.