Combined method for producing low sulfur diesel oil

The invention relates to a combined method for producing low sulfur diesel oil. Fresh raw oil enters an adsorption reactor and is adsorbed to produce adsorbed effluent, the liquid raw material enters a hydrogen mixer after adsorption, and the adsorbed adsorbent enters an adsorbent regenerator and is regenerated for recycling; hydrogen, the liquid raw material and recycled oil are mixed in the hydrogen mixer to form pre-saturated liquid flow, the pre-saturated liquid flow serving as a raw material enters a single-stage or multi-stage hydrogenation reactor with internal members and is hydrogenated, and the gaseous product is discharged out of the reactor during reaction; a part of the liquid reaction product serving as recycled oil enters the hydrogen mixer; and the other part of the reaction product enters a first separator in the form of a product for separating, the separated gaseous product is discharged out of the separator, the liquid product enters a second separator, and the final product is separated from the second separator. The method for sulfur and aromatic hydrocarbon removal of diesel oil can effectively reduce the liquid hydrogenation load, reduce the consumption of the recycled oil or solvent oil and improve the hydrogenation efficiency.