摘要： As one of the important photonic integrated platforms, microcavity resonators based on silicon nitride (SiN) have great potential in nonlinear optics applications due to their low loss and high nonlinearity. They are usually designed with a multi-mode structure to achieve high quality factors (Q factors) and small mode volumes, which are beneficial for enhancing light-matter interactions. However, the multi-mode nature also introduces challenges in controlling the coupling between different modes, especially for high-order modes. In this work, we demonstrate a detailed coupling identification of high-Q SiN microresonators with a multi-mode structure. By carefully designing the coupling region between the bus waveguide and the microresonator, we achieve selective excitation of different modes and investigate their coupling characteristics. Our results show that the coupling strength can be effectively controlled by adjusting the gap size and the coupling length, which provides a useful guideline for optimizing the performance of SiN microresonators in nonlinear optics applications.