Aiming at the difficulty of achieving critical coupling conditions for aluminum nitride microring resonators， an aluminum nitride bending-coupled microring resonator is designed and prepared. Through the analysis of the coupling coefficient formula of the microring resonator， the advantages and disadvantages of various solutions to improve the coupling strength are respectively explained. Finally， a curved coupling zone structure is selected to enhance the coupling strength， and a solution to achieve critical coupling conditions under a wide coupling gap is obtained. A high-quality aluminum nitride single crystal film is grown on a sapphire substrate. Conductive glue is used to overcome the non-conductivity of the material. The electron beam exposure system is used to make the bending angle of 40°， the coupling gap of 0.190 μm， and the waveguide width of 0.41 μm. The microring resonant cavity is patterned， a number of aluminum nitride etching parameters are analyzed and optimized， and the pattern is finally transferred to the aluminum nitride layer to obtain a curved coupled aluminum nitride microring resonant cavity with uniform coupling gap and flat sidewalls. This research provides a reference for the selection of critical coupling conditions for aluminum nitride microring resonators.