A 3D ultrasonic imaging apparatus comprises an ultrasonic probe assembly (1) and an echo analysis apparatus (2). The probe comprises a probe housing (10), an acoustical window structure (11), an ultrasonic transducer (12), and the echo analysis apparatus (2). The acoustical window structure (11) is attached to the probe housing (10) to form a sealed chamber. The surface of the acoustical window (11) is in direct contact with a breast of an examined human body. An acoustical head of the ultrasonic transducer (12) performs reciprocating movement in a first speed in the sealed chamber, and performs high-speed scanning on the breast of the examined human body by means of the surface of the acoustical window structure (11), so as to obtain an initial ultrasonic signal. The echo analysis apparatus (2) is used for analyzing the initial ultrasonic signal, and determining the quality of an ultrasonic image obtained in a manner that the ultrasonic transducer (12) performs high-speed scanning. The ultrasonic transducer (12) performs reciprocating movement in a second speed in the sealed chamber, so as to perform scanning again to obtain an ultrasonic signal. A 3D ultrasonic imaging method. Ultrasonic data is obtained by performing high-speed scanning, so as to assess the quality of the contact or the coupling between the ultrasonic probe and a human body tissue, and after adjustment, scanning is performed again at a second speed, thereby improving the success rate of mammary gland scans.La présente invention concerne un appareil d'échographie en 3D qui comprend un ensemble sonde ultrasonore (1) et un appareil d'analyse d'échos (2). La sonde comprend un boîtier de sonde (10), une structure de fenêtre acoustique (11), un transducteur à ultrasons (12), et l'appareil d'analyse d'écho (2). La structure de fenêtre acoustique (11) est fixée au boîtier de sonde (10) pour former une chambre scellée. La surface de la fenêtre acoustique (11) est en contact direct avec un sein du corps hu
