To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks, Pd-catalyzed one-pot reactions between pyridyl-substituted nido-carboranes and alkynes directly afford two distinct types of 2D-3D fused carboranyl polycyclic compounds: 3a-3f, 4a-4d. The structures of this series of compounds were characterized by nuclear magnetic resonance spectroscopy, single-crystal X-ray diffraction, and high-resolution mass spectrometry, and a plausible reaction mechanism was proposed. Crystal structures reveal that the multiple rings in such 2D-3D fused carboranyl polycyclic compounds exhibit a certain degree of coplanarity. Furthermore, these compounds exhibited properties distinct from those of conventional 2D polycyclic systems.