Process for the production of simple sugars starting from a cellulose material, comprising the steps of: feeding a continuous flow of the said cellulose material or a mixture composed of said-cellulose material and water to a turbo-reactor comprising a horizontal-axis cylindrical tubular body, provided with at least one opening (5, 6) for introducing said cellulose material or said mixture and reagents, at least one discharge opening of the treated material, a heating jacket for bringing the inner wall of the tubular body to a predetermined temperature, a bladed rotor, rotatably supported in the cylindrical tubular body where it is put in rotation at speeds in the range of 15-40 m/s, so as to disperse said continuous flow of cellulose material or said mixture in a flow of cellulose material particles, feeding into said turbo-reactor, in co-current with said flow of cellulose material or with said mixture, a continuous and finely subdivided flow of a reagent capable of breaking the integrity of the molecular structure of said cellulose material, making it particularly accessible for being digested during an enzymatic treatment, centrifuging said particles of cellulose material and said reagent against the inner wall of the turbo-reactor, heated to a temperature of at least 150°C, with formation of a highly turbulent, dynamic, thin tubular fluid layer, wherein the cellulose material particles and said reagent are mechanically maintained in close contact by the blades of said bladed rotor, making said cellulose material and said reagent react in said thin layer while it advances in substantial contact with said inner wall of the turbo-reactor towards the discharge opening, continuously discharging a flow of treated cellulose material, sending said flow of treated cellulose material to an enzymatic digestion step with the addition of a sufficient quantity of enzymes, said enzymes being specific for hydrolysing said treated cellulose material with the obtainment of said simple sugars, wherein said flow of cellulose material or said mixture and said reagent flow are premixed with each other in a turbo-mixer placed upstream of said turbo-reactor, said turbo-mixer comprising a horizontal-axis cylindrical tubular body, provided with inlet openings (25, 26) of said cellulose material or said mixture and said reagent, at least one discharge opening of the cellulose material premixed with said reagent, a heating/cooling jacket for bringing the inner wall of the tubular body to a predetermined temperature in the range of 10-100°C, and a bladed rotor, rotatably supported in the cylindrical body where it is put in rotation at peripheral speeds in the range of 15-40 m/s, so as to premix said continuous flow of cellulose material or said mixture with said continuous reagent flow in a continuous flow of premixed material. feeding a continuous flow of the said cellulose material or a mixture composed of said-cellulose material and water to a turbo-reactor comprising a horizontal-axis cylindrical tubular body, provided with at least one opening (5, 6) for introducing said cellulose material or said mixture and reagents, at least one discharge opening of the treated material, a heating jacket for bringing the inner wall of the tubular body to a predetermined temperature, a bladed rotor, rotatably supported in the cylindrical tubular body where it is put in rotation at speeds in the range of 15-40 m/s, so as to disperse said continuous flow of cellulose material or said mixture in a flow of cellulose material particles, feeding into said turbo-reactor, in co-current with said flow of cellulose material or with said mixture, a continuous and finely subdivided flow of a reagent capable of breaking the integrity of the molecular structure of said cellulose material, making it particularly accessible for being digested during an enzymatic treatment, centrifuging said particles of cellulose material and said reagent against the inner wall of the turbo-reactor, heated to a temperature of at least 150°C, with formation of a highly turbulent, dynamic, thin tubular fluid layer, wherein the cellulose material particles and said reagent are mechanically maintained in close contact by the blades of said bladed rotor, making said cellulose material and said reagent react in said thin layer while it advances in substantial contact with said inner wall of the turbo-reactor towards the discharge opening, continuously discharging a flow of treated cellulose material, sending said flow of treated cellulose material to an enzymatic digestion step with the addition of a sufficient quantity of enzymes, said enzymes being specific for hydrolysing said treated cellulose material with the obtainment of said simple sugars, wherein said flow of cellulose material or said mixture and said reagent flow are premixed with each other in a turbo-mixer placed upstream of said turbo-reactor, said turbo-mixer comprising a horizontal-axis cylindrical tubular body, provided with inlet openings (25, 26) of said cellulose material or said mixture and said reagent, at least one discharge opening of the cellulose material premixed with said reagent, a heating/cooling jacket for bringing the inner wall of the tubular body to a predetermined temperature in the range of 10-100°C, and a bladed rotor, rotatably supported in the cylindrical body where it is put in rotation at peripheral speeds in the range of 15-40 m/s, so as to premix said continuous flow of cellulose material or said mixture with said continuous reagent flow in a continuous flow of premixed material.