The invention discloses an ultrasonic wave head wave phase reversal testing method for the depth of a shallow fracture in the surface of concrete. The method includes the following steps that (1), floating dust and dirt on the surface of a measured object are removed, whether water or steel bars or other foreign bodies exist in the fracture or not is observed, and it is guaranteed that the measured object is dry; (2), ultrasonic wave measuring points are symmetrically arranged in pairs with the measured fracture serving as the center, the measuring points are numbered in pairs, and each measuring distance is the distance between the inner edges of each pair of transducers; (3), ultrasonic wave measuring points are arranged on one side of the measured facture in pairs, the measuring points are numbered in pairs, and each measuring distance is the distance between the inner edges of each pair of transducers; (4), sound and time measurement without fracture crossing is conducted; (5), sound and time measurement with fracture crossing is conducted; (6), in the measurement with fracture crossing, when head wave phase reversal is found in a certain measuring distance, the depth value of the fracture is calculated through measured values of the measuring distance and two adjacent measuring distances. By means of the ultrasonic wave head wave phase reversal testing method, whether ultrasonic waves diffract to the bottom of the fracture or not is judged by observing the head wave phase change, and then the depth of the shallow fracture in the surface of the concrete is accurately detected.