The invention belongs to the technical field of environment protection, and particularly relates to a printing ink sludge harmless recycling treatment process and system. The characteristic that printing ink sludge contains a lot of carbon black and organic matter is fully taken into consideration, a high-temperature pyrolytic process is adopted in an airtight environment to completely pyrolyze the printing ink sludge after being dried, and generated high-temperature pyrolysis gas contains a lot of inflammable gas; a dedusting device is adopted to remove dust in the high-temperature pyrolysisgas, a condensing device is adopted to obtain bio-oil from gaseous oil and vapor which can be condensed and liquiefied in the pyrolysis gas with the help of an oil-water separation device, and purified fuel gas is obtained after gas which cannot be condensed is purified through a fuel gas purifying device; both the bio-oil and the purified fuel gas are obtained from the printing ink sludge and canbe reutilized for harmless treatment of the same to provide most energy for the drying process, and the short part is supplied by the outside. The treatment process realizes harmless recycling of theprinting ink sludge; waste is used to treat waste, so that the treatment process is economical and environment-friendly.