The invention discloses a high-efficiency heavy inferior oil conversion process. According to the process, a plug flow suspended bed hydrogenation reactor is adopted together with a two-section fluidized bed hydrogenation reactor, the advantages of the two reactors are fully taken, a gas-liquid separation system is optimized, and heavy inferior oil with high asphalt, high metal, high carbon residue and high sulfur can be treated. The high-efficiency heavy inferior oil conversion process has the characteristics that the raw material adaptability is high, the conversion rate is high, the yield is high, the energy consumption is small, the product quality is good, and the like.