Abstract: To improve the mixing efficiency of microchannel mixers, it is necessary to increase the output pressure of the driving source to overcome the pressure drop in high-resistance microchannels. In this paper, a piezoelectric-driven micromixer is proposed, which uses an energy-storage piezoelectric pump as the driving source and incorporates a spiral mixing microchannel with airfoil baffles. First, the pressure stabilization mechanism of the energy-storage gas tank is theoretically analyzed, and the relationship between the gas pressure and the liquid level height in the tank is derived. Second, the output performance of the energy-storage piezoelectric pump and the spiral microchannel mixer is experimentally investigated. Finally, the BaSO₄ coprecipitation reaction is used as the characterization system, and the mixing performance of the piezoelectric-driven helical microchannel mixer is verified by comparing the mixing effects under different mixing modes. The results show that the maximum output back pressure of the energy-storage piezoelectric pump reaches 10021 Pa, which is 92% higher than that of the duckbill-valve piezoelectric pump without a gas tank. The BaSO₄ particles prepared by the proposed mixer have particle sizes of 200～300 nm and are uniformly dispersed. Energy-dispersive spectroscopy indicates the strongest Ba²⁺ signal and the lowest Na⁺ residue. This study demonstrates that integrating the gas tank into the energy-storage piezoelectric pump increases the output back pressure from 5207 Pa to 10021 Pa, significantly improving the pump’s ability to drive high-resistance microchannels. Moreover, the synergistic effect of the piezoelectric drive and the spiral airfoil baffle structure contributes more to the improvement of mixing efficiency than merely changing the channel geometry. This study can provide reliable technical support for the rapid preparation of nanomaterials.