A dual-cavity fluid conveying apparatus, for delivering a fluid, comprising: - a flow-converging device, including: - two sides (211, 212) corresponding to each other; - a first channel and a second channel, both of the first channel and the second channel passing through the two sides (211, 212); and - an inlet passage and an outlet passage, both of the inlet passage and the outlet passage being arranged between the two sides (211, 212), and being communicated with the first channel and the second channel, respectively; - a first cavity body, and a second cavity body, being symmetrically disposed at the two sides (211, 212) of the flow-converging device, wherein the first cavity body and the second cavity body each includes: - a valve cover (22, 22'), being disposed on one of the two sides (211, 212) of the flow-converging device; - a valve membrane (23, 23'), being interposed between one of the two sides (211, 212) of the flow-converging device and the valve cover (22, 22'); and - an actuating device (24, 24'), being disposed circumferentially on the valve cover (22, 22') so as to define, together with the valve cover (22, 22'), a pressure chamber (225, 225'), characterized in that: - wherein both of the first cavity body and the second cavity body further comprise a plurality of seal rings (26, 27), the plurality of seal rings (26, 27) are disposed on the two sides (211, 212) of the flow-converging device and in a plurality of recesses (217, 227, 217', 227') located on the valve cover (22, 22') of both of the first cavity body and the second cavity body; and part of each of the plurality of seal rings (26, 27) protrudes from each of the plurality of recesses (217, 227, 217', 227'), for applying a preforce to the valve membrane (23, 23'). - a flow-converging device, including: - two sides (211, 212) corresponding to each other; - a first channel and a second channel, both of the first channel and the second channel passing through the two sides (211, 212); and - an inlet passage and an outlet passage, both of the inlet passage and the outlet passage being arranged between the two sides (211, 212), and being communicated with the first channel and the second channel, respectively; - two sides (211, 212) corresponding to each other; - a first channel and a second channel, both of the first channel and the second channel passing through the two sides (211, 212); and - an inlet passage and an outlet passage, both of the inlet passage and the outlet passage being arranged between the two sides (211, 212), and being communicated with the first channel and the second channel, respectively; - a first cavity body, and a second cavity body, being symmetrically disposed at the two sides (211, 212) of the flow-converging device, wherein the first cavity body and the second cavity body each includes: - a valve cover (22, 22'), being disposed on one of the two sides (211, 212) of the flow-converging device; - a valve membrane (23, 23'), being interposed between one of the two sides (211, 212) of the flow-converging device and the valve cover (22, 22'); and - an actuating device (24, 24'), being disposed circumferentially on the valve cover (22, 22') so as to define, together with the valve cover (22, 22'), a pressure chamber (225, 225'), characterized in that: - a valve cover (22, 22'), being disposed on one of the two sides (211, 212) of the flow-converging device; - a valve membrane (23, 23'), being interposed between one of the two sides (211, 212) of the flow-converging device and the valve cover (22, 22'); and - an actuating device (24, 24'), being disposed circumferentially on the valve cover (22, 22') so as to define, together with the valve cover (22, 22'), a pressure chamber (225, 225'), characterized in that: - wherein both of the first cavity body and the second cavity body further comprise a plurality of seal rings (26, 27), the plurality of seal rings (26, 27) are disposed on the two sides (211, 212) of the flow-converging device and in a plurality of recesses (217, 227, 217', 227') located on the valve cover (22, 22') of both of the first cavity body and the second cavity body; and part of each of the plurality of seal rings (26, 27) protrudes from each of the plurality of recesses (217, 227, 217', 227'), for applying a preforce to the valve membrane (23, 23').