A shredding method for obtaining nanocellulose of the types which are mechanical and based on a bleached cellulose diluted in water, the bleached cellulose being subjected in a combined manner to pressure, acceleration, speed, friction, turbulence, expansion, wherein the method is based on a solution comprising a bleached cellulose diluted in water in a percentage from 1% to 6%, said solution being subjected to: - a pressure of between 250 and 600 bar in a compression chamber in order to force the passage of the solution through a nozzle. - forced passage of the compressed solution through a nozzle in which: a) in a frustoconical inlet having a length of about 5 mm with an outer ring perimeter matching the compression chamber, greater than an inner ring perimeter which will match the perimeter of the passage, the solution goes from a speed of about 0.02 m/s in the compression chamber to a speed of between 50 m/s and 250 m/s in the nozzle, giving rise to a first shredding of the solution. b) in the cylindrical passage and with the solution being at a pressure of between 250 and 600 bar and at a speed of between 50 m/s and 250 m/s, a friction occurs in the perimetral wall of the tubular passage, which causes a turbulent regimen in the solution, causing a second shredding. c) in a frustoconical outlet of the nozzle, arranged inversely with respect to that of the inlet, the start of an expansion and decompression of the solution is caused, - expansion, decompression, and collision of the solution at the outlet of the nozzle where the solution rushes into a receiving chamber which is at a pressure of between zero to between less than 250 and less than 600 bar, which causes an expansion and decompression of the solution which, along with the speed with which the solution exits the nozzle, causes the collision of the solution against all the walls of the receiving chamber, and particularly against a wall functioning as a dead center, which is arranged facing the frustoconical outlet of the nozzle at a distance of between 15 mm and 150 mm, which again causes a third shredding of the solution, thereby obtaining the shredding and the nanocellulose. - a pressure of between 250 and 600 bar in a compression chamber in order to force the passage of the solution through a nozzle. - forced passage of the compressed solution through a nozzle in which: a) in a frustoconical inlet having a length of about 5 mm with an outer ring perimeter matching the compression chamber, greater than an inner ring perimeter which will match the perimeter of the passage, the solution goes from a speed of about 0.02 m/s in the compression chamber to a speed of between 50 m/s and 250 m/s in the nozzle, giving rise to a first shredding of the solution. b) in the cylindrical passage and with the solution being at a pressure of between 250 and 600 bar and at a speed of between 50 m/s and 250 m/s, a friction occurs in the perimetral wall of the tubular passage, which causes a turbulent regimen in the solution, causing a second shredding. c) in a frustoconical outlet of the nozzle, arranged inversely with respect to that of the inlet, the start of an expansion and decompression of the solution is caused, a) in a frustoconical inlet having a length of about 5 mm with an outer ring perimeter matching the compression chamber, greater than an inner ring perimeter which will match the perimeter of the passage, the solution goes from a speed of about 0.02 m/s in the compression chamber to a speed of between 50 m/s and 250 m/s in the nozzle, giving rise to a first shredding of the solution. b) in the cylindrical passage and with the solution being at a pressure of between 250 and 600 bar and at a speed of between 50 m/s and 250 m/s, a friction occurs in the perimetral wall of the tubular passage, which causes a turbulent regimen in the solution, causing a second shredding. c) in a frustoconical outlet of the nozzle, arranged inversely with respect to that of the inlet, the start of an expansion and decompression of the solution is caused, - expansion, decompression, and collision of the solution at the outlet of the nozzle where the solution rushes into a receiving chamber which is at a pressure of between zero to between less than 250 and less than 600 bar, which causes an expansion and decompression of the solution which, along with the speed with which the solution exits the nozzle, causes the collision of the solution against all the walls of the receiving chamber, and particularly against a wall functioning as a dead center, which is arranged facing the frustoconical outlet of the nozzle at a distance of between 15 mm and 150 mm, which again causes a third shredding of the solution, thereby obtaining the shredding and the nanocellulose.