A composite sound-absorbing device with at least one built-in resonant cavity, including: a perforated board having a number of first pores thereon, a back board and side boards, said perforated board, back board and side boards forming a closed cavity, wherein: at least one resonant cavity is located within said closed cavity, each of said at least one resonant cavity having a volume of V=10mm 3 -1×10 10 mm 3, the thickness of the wall thereof being 0.05mm-10mm; at least two second pores are located on a wall of each of said at least one resonant cavity; each of said second pores has an aperture of d'=0.05-100mm, with a perforation rate σ'=0.01%-30%; the sound-absorbing device further including: at least one tube, each tube being associated with a corresponding resonant cavity and a corresponding first pore on the perforated board, wherein for each resonant cavity: one of said second pores is connected to one end of the corresponding tube located within said closed cavity for increasing acoustical impedance; the other end of said corresponding tube is connected to the corresponding first pore on said perforated board; and the other ones of said second pores are connected with said closed cavity; and wherein said tubes are made of metal, glass, plastic or rubber, with a length of 1-5000mm and diameter of 0.1-100mm; and when said tubes are made of rubber, they are connected to said first pores and second pores via binding, or they are connected to said first pores via a first transition joint at the ends of said tubes, and they are connected to said second pores via a second transition joint at the ends of said tubes; when said tubes are made of metal, glass or plastic, they are connected to said first pores and second pores via binding, welding, thread connection or injection, or they are connected to said first pores via a first transition joint at the ends of said tubes, and they are connected to said second pores via a second transition joint at the ends of said tubes. at least one resonant cavity is located within said closed cavity, each of said at least one resonant cavity having a volume of V=10mm 3 -1×10 10 mm 3, the thickness of the wall thereof being 0.05mm-10mm; at least two second pores are located on a wall of each of said at least one resonant cavity; each of said second pores has an aperture of d'=0.05-100mm, with a perforation rate σ'=0.01%-30%; the sound-absorbing device further including: at least one tube, each tube being associated with a corresponding resonant cavity and a corresponding first pore on the perforated board, wherein for each resonant cavity: one of said second pores is connected to one end of the corresponding tube located within said closed cavity for increasing acoustical impedance; the other end of said corresponding tube is connected to the corresponding first pore on said perforated board; and the other ones of said second pores are connected with said closed cavity; and wherein said tubes are made of metal, glass, plastic or rubber, with a length of 1-5000mm and diameter of 0.1-100mm; and when said tubes are made of rubber, they are connected to said first pores and second pores via binding, or they are connected to said first pores via a first transition joint at the ends of said tubes, and they are connected to said second pores via a second transition joint at the ends of said tubes; at least one tube, each tube being associated with a corresponding resonant cavity and a corresponding first pore on the perforated board, wherein for each resonant cavity: one of said second pores is connected to one end of the corresponding tube located within said closed cavity for increasing acoustical impedance; the other end of said corresponding tube is connected to the corresponding first pore on said perforated board; and the other ones of said second pores are connected with said closed cavity; one of said second pores is connected to one end of the corresponding tube located within said closed cavity for increasing acoustical impedance; the other end of said corresponding tube is connected to the corresponding first pore on said perforated board; and the other ones of said second pores are connected with said closed cavity; and wherein said tubes are made of metal, glass, plastic or rubber, with a length of 1-5000mm and diameter of 0.1-100mm; and when said tubes are made of rubber, they are connected to said first pores and second pores via binding, or they are connected to said first pores via a first transition joint at the ends of said tubes, and they are connected to said second pores via a second transition joint at the ends of said tubes; when said tubes are made of metal, glass or plastic, they are connected to said first pores and second pores via binding, welding, thread connection or injection, or they are connected to said first pores via a first transition joint at the ends of said tubes, and they are connected to said second pores via a second transition joint at the ends of said tubes. they are connected to said first pores and second pores via binding, welding, thread connection or injection, or they are connected to said first pores via a first transition joint at the ends of said tubes, and they are connected to said second pores via a second transition joint at the ends of said tubes.