The invention discloses a combined process of hydrotreatment and light fraction-conversion for
residual oil. The combined process comprises the following steps: (1) allowing an inferior heavy oil feedstock to enter into a
solvent deasphalting device so as to obtain deasphalted oil and de-oiled
asphalt; (2) mixing the de-oiled
asphalt obtained in step (1) with at least a part of oil
slurry and allowing an obtained mixture to enter into a
fluidized bed hydrotreatment unit for
fluidized bed hydrotreatment; (3) mixing an
effluent of
fluidized bed hydrotreatment obtained in the step (2) with the deasphalted oil, adding at least a part of recycle oil of a catalytic
cracking unit at the same time and allowing an obtained mixture to enter into a
fixed bed hydrotreatment unit, wherein generated oil of an
effluent of
fixed bed hydrotreatment is used as a feedstock for the catalytic
cracking unit; and (4) carrying out treatment in a fractionating
tower of the catalytic
cracking unit so as to obtain catalytic
cracking reaction products including a
gasoline fraction, a diesel oil fraction, recycle oil and oil
slurry. Compared with the prior art, the combined process provided by the invention has the advantages of wide sources of the feedstocks, low equipment investment, stable operation, a long operation period and a good synergistic and coordination effect.