The invention provides an auto-coupling acoustic wave test system and an acoustic wave test method. The auto-coupling acoustic wave test system mainly comprises two parts including an acoustic wave test device and a water injection and pressurization device, wherein the acoustic wave test device comprises an acoustic wave probe (1), one end of the acoustic wave probe (1) is provided with a water inlet connector (13), the water inlet connector (13) is provided with a water inlet hole (7), an acoustic wave signal cable channel hole (8) and a push rod connecting bolt (14), and the other end of the acoustic wave probe (1) is provided with a fixed short rod (4), and is characterized in that the acoustic wave test device also comprises a flexible weakly permeable bag (2) sleeving the outside of the acoustic wave probe (1), and comprising a sealing section and a working section. Since the flexible weakly permeable bag is adopted, the flexibility can ensure that one type can adapt to bore diameters of different sizes. The weak permeability eliminates the need of exhaust vents at the end part, can ensure the position between a working section bag and a hole wall is filled with water, and can effectively ensure the coupling of the probe in a test section and the hole wall.