A novel Hoffmann-type metal-organic framework ultra-wide bandgap semiconductor material, {Ni(DMA)2[Ni(CN)4]}(DMA denotes dimethylamine), has been predicted. The material has been named Ni-DMA-Ni, and its structure, stability, electronic, mechanical, optical, and transport properties have been investigated by first-principles simulations. The calculation results demonstrate that Ni-DMA-Ni exhibits excellent thermal and dynamics stability at room temperature, with a bandgap value as high as 4.89 eV and the light absorption capacity reaches 105 cm-1 level in the deep ultraviolet region. The Young's modulus is 27.94 GPa, and the shear modulus is 10.82 GPa, indicating mechanical anisotropy. In addition, the construction of a two-probe device utilizing Ni-DMA-Ni to evaluate its transport properties revealed a negative differential resistance effect in its I-V characteristic curve. These unique properties highlight the potential application of the Ni-DMA-Ni material in the deep ultraviolet optoelectronic field. This study provides novel concepts and contributes significant insights to the research of Hoffmann-type semiconductor materials in the field of optoelectronic devices.