Based on the flow induced motion energy conversion system, the combined triangular prisms with the section form and stiffness as variables to evaluate the amplitude, frequency and other indicators was studied. The combined triangular prisms were selected for model test, as well as the influence of arrangement and stiffness on the combined triangular prisms were studied by changing the arrangement of the prisms and system stiffness. The aim is to explore the optimal condition for flow induced motion of the three triangular prisms in different arrangements, and to expand ideas for subsequent research on flow induced motion of multiple oscillators. The experimental results show that all the combined triangular prisms have good performance with different stiffness. Both the motion of type I prism and type III prism perform typical vortex induced vibration with the increase of flow velocity, the type I prism has the best performance.