The invention provides a thickness mould piezoelectric cavity-coupling transducer based on a dual-matching-layer structure. The thickness mould piezoelectric cavity-coupling transducer comprises a piezoelectric plate (1), a first matching layer (2), a second matching layer (3), a transducer housing (4), a rear cover plate (5) and an interface (6), wherein the piezoelectric plate (1), the first matching layer (2) and the second matching layer (3) are sequentially arranged in the transducer housing (4) in an ultrasonic signal emitting direction; the first matching layer (2) is a circular sheet-shaped structure which is formed by mixing and curing hollow glass micro ball powder (9) and epoxy resin (8); the second matching layer (3) is a circular sheet-shaped structure prepared by micro-pore foamed polymer; the diameters of the first matching layer (2) and the second matching layer (3) are the same as that of the piezoelectric plate (1). The transducer adopts a multi-matching-layer design to synthesize matching layers which are suitable for acoustic impedance and are manufactured of different porous materials, so that sensitivity of the cavity-coupling transducer is greatly improved.