A miniature fluid control device for transporting gas, comprising: a gas inlet plate comprising a feeding surface and a coupling surface opposing to the feeding surface, wherein at least one inlet is formed in the feeding surface, at least one convergence channel and a circular cavity are concavely formed in the coupling surface, wherein the circular cavity has a first diameter, a first end of the convergence channel is in communication with the circular cavity, a second end of the convergence channel is in communication with the at least one inlet, and a convergence chamber is defined by the circular cavity, wherein after the gas is introduced into the at least one convergence channel through the at least one inlet, the gas is guided by the at least one convergence channel and converged to the convergence chamber; a resonance plate having a central aperture corresponding to the circular cavity of the gas inlet plate; and a piezoelectric actuator comprising a suspension plate, an outer frame, at least one bracket and a piezoelectric plate, wherein the suspension plate has a first surface and an opposing second surface, a cylindrical bulge is formed on the second surface of the suspension plate, the cylindrical bulge and the circular cavity are aligned with each other along a vertical direction, the cylindrical bulge has a second diameter, wherein the outer frame is arranged around the suspension plate, the suspension plate and the outer frame are connected with each other through at least one bracket, and the piezoelectric plate is attached on the first surface of the suspension plate, wherein the gas inlet plate, the resonance plate and the piezoelectric actuator are stacked on each other sequentially, and a gap is formed between the resonance plate and the piezoelectric actuator to define a first chamber, wherein after a gas is fed into the at least one inlet of the gas inlet plate, the gas is converged to the circular cavity through the at least one convergence channel, transferred through the central aperture of the resonance plate, introduced into the first chamber, transferred downwardly through a vacant space between the at least one bracket of the piezoelectric actuator, and exited from the miniature fluid control device, by which the miniature fluid control device continuously outputs the transported gas, wherein each of the suspension plate and the piezoelectric plate has a square shape and the side length of the suspension plate is in a range between 8mm-9mm, characterized in that a specified ratio of the second diameter to the first diameter is in a range between 0.95 and 1.15, and the operating frequency is in a range between 22kHz-27kHz, which affects gas pressure of the transported gas, wherein the operating frequency is increased as the side length of the suspension plate is reduced. a gas inlet plate comprising a feeding surface and a coupling surface opposing to the feeding surface, wherein at least one inlet is formed in the feeding surface, at least one convergence channel and a circular cavity are concavely formed in the coupling surface, wherein the circular cavity has a first diameter, a first end of the convergence channel is in communication with the circular cavity, a second end of the convergence channel is in communication with the at least one inlet, and a convergence chamber is defined by the circular cavity, wherein after the gas is introduced into the at least one convergence channel through the at least one inlet, the gas is guided by the at least one convergence channel and converged to the convergence chamber; a resonance plate having a central aperture corresponding to the circular cavity of the gas inlet plate; and a piezoelectric actuator comprising a suspension plate, an outer frame, at least one bracket and a piezoelectric plate, wherein the suspension plate has a first surface and an opposing second surface, a cylindrical bulge is formed on the second surface of the suspension plate, the cylindrical bulge and the circular cavity are aligned with each other along a vertical direction, the cylindrical bulge has a second diameter, wherein the outer frame is arranged around the suspension plate, the suspension plate and the outer frame are connected with each other through at least one bracket, and the piezoelectric plate is attached on the first surface of the suspension plate, wherein the gas inlet plate, the resonance plate and the piezoelectric actuator are stacked on each other sequentially, and a gap is formed between the resonance plate and the piezoelectric actuator to define a first chamber, wherein after a gas is fed into the at least one inlet of the gas inlet plate, the gas is converged to the circular cavity through the at least one convergence channel, transferred through the central aperture of the resonance plate, introduced into the first chamber, transferred downwardly through a vacant space between the at least one bracket of the piezoelectric actuator, and exited from the miniature fluid control device, by which the miniature fluid control device continuously outputs the transported gas, wherein each of the suspension plate and the piezoelectric plate has a square shape and the side length of the suspension plate is in a range between 8mm-9mm, characterized in that a specified ratio of the second diameter to the first diameter is in a range between 0.95 and 1.15, and the operating frequency is in a range between 22kHz-27kHz, which affects gas pressure of the transported gas, wherein the operating frequency is increased as the side length of the suspension plate is reduced.