The invention aims at providing a low-frequency drum-type active and passive compound sound-attenuating system for a fluid-filled pipeline. The low-frequency drum-type active and passive compound sound-attenuating system for the fluid-filled pipeline comprises an upstream outer tube head, a rectangular housing, a downstream outer tube head and a plate-type membrane structure. Two ends of the rectangular housing are connected with the upstream outer tube head and the downstream outer tube head correspondingly. The plate-type membrane structure is arranged in the rectangular housing and fixed to the upstream outer tube head and the downstream outer tube head. The plate-type membrane structure, the rectangular housing, the upstream outer tube head and the downstream outer tube head form a closed back-cavity. The downstream outer tube head is connected with a downstream pipe and a first hydrophone is mounted on the upstream outer tube head. Water pressure sensors, and pressure balancing devices which fill the back-cavity with gas are arranged on the downstream outer tube head, and a second hydrophone is mounted on the downstream pipe. The low-frequency drum-type active and passive compound sound-attenuating system for the fluid-filled pipeline breaks through the conventional passive sound-attenuating structure and produces a reflection action on incident sound waves to realize resistance and noise reduction through a drum-type configuration which is formed by the flexible plate-type membrane structure and the closed back-cavity. The fluid-filled flowing pipeline reduces resistance loss without abrupt change of the section structure.