Cyanoformaldehyde [HC(O)CN], a detected interstellar molecule, exhibits potential isomeric transformations that remain incompletely understood. Understanding its conformational flexibility is crucial for predicting its reactivity in interstellar conditions. This study presents a comprehensive investigation of the complete HC(O)CN potential energy surface (PES) using the anharmonic downward distortion following (ADDF) algorithm, enabling exhaustive mapping of EQs, TSs, DCs, and connecting pathways. At the B3LYP-D3(BJ)/def2-TZVP level of theory, our analysis reveals 48 EQs, 152 TSs, and 49 DCs. We identify 80 unique isomerization pathways mediated by TS structures (EQ