To improve the output flow of a valve-less piezoelectric pump and to analyze the effects on the pump′s output flow with no-moving-parts (triangular prism group) parameters, a valve-less piezoelectric pump is designed and produced with 3D printing technology that has five different groups of parameters for its triangular prism bluff bodies, and flow tests are carried out for each group. First, the structure and working principle of the piezoelectric pump are analyzed. Second, the formula for the pump′s flow rate is established and obtain the expression between pump flow and parameters of triangular prisms, the relationship between the positive and negative flow resistance ratio of the three prism, the relationship between the number of the three prisms and the pump output flow is drawn with MATLAB software. Experimental results show the following. With constant driving voltage and driving frequency, the triangular prism group′s parameters all greatly impact the pump′s output flow. The output flow increases with a growth of numbers and increased height of triangular prisms, decreases as the gap between the triangular prism and one-way pump chamber increases, and decreases with increased apex angle of the triangular prism. The output flow also increases with a growth of the gap, but decreases after the gap reaches a certain value.