The invention discloses a preparation method for calcining a low-hydration heat Portland cement clinker from oil-based drill cuttings, and relates to the technical field of oil-based drill cutting treatment. The preparation method comprises the following steps: pretreating diesel oil-based drill cuttings, uniformly mixing limestone, a high-iron aluminum waste stone, the pretreated diesel oil-baseddrill cuttings and non-ferrous metal slag according to a certain ratio, then grinding into raw meal, then feeding the raw meal into a novel dry-process rotary kiln, performing high-temperature calcination, and cooling to obtain the clinker. By the preparation method, major difficulties troubling oilfield drilling exploitation can be overcome, enrichment of heavy metal ions such as copper, zinc, lead, chromium, mercury and barium in the diesel oil-based drill cuttings in nature can be reduced, and damage to groundwater and soil can be reduced; diesel oil and organic substances in the drill cuttings can provide heat in the clinker calcinating process, so that the energy consumption of the clinker can be significantly reduced, the CO2 emission can be reduced, the clinker calcinating temperature can be lowered, the outputs of a cement mill and the rotary kiln are obviously increased, the burnability of the raw meal is enhanced, the liquid phase content of the clinker is increased, latticedefects of dicalcium silicate in the clinker are increased, the activity of the dicalcium silicate is improved, and the hydration heat value of cement is reduced.