The invention discloses a compression degree testing method of shield tunneling machine empty push tunnel segments. The method includes the steps of firstly, taking two tunnel segment test pieces; secondly, debugging an ultrasonic flaw detector to allow each part of the ultrasonic flaw detector to work normally; thirdly, selecting the transducer of the ultrasonic flaw detector; fourthly, performing ultrasonic flaw detection on the tunnel segment test pieces; fifthly, entering a project construction site to perform ultrasonic flaw detection on on-site tunnel segments; sixthly, comparing the ultrasonic transit time, wave velocity and wave amplitude data obtained by detecting under each detecting interval in the fifth step with the ultrasonic transit time, wave velocity and wave amplitude data obtained by detecting under each detecting interval in the fourth step to obtain the compression condition of two adjacent on-site tunnel segments of the project construction site. The testing method has the advantages that the compression degree of the shield tunneling machine empty push tunnel segments is visually presented in a digital manner so as to accurately detect the compression degree of the shield tunneling machine empty push tunnel segments, the detection efficiency is increased, and construction quality is guaranteed.