To provide a method for producing acrylic resins by an extruder for greatly improving reactivity and reaction uniformity by reducing extrusion fluctuation and for suppressing foreign matter and defects derived from a resin in the acrylic resin.

In the method for producing acrylic resins, an acrylic resin is produced by means of a tandem type reactive extruder having a first extruder 1 wherein a solid resin material is plasticized, and a reagent of a first step reaction is fed 5 for performing a reaction; a second extruder 2 wherein a reagent (auxiliary material) of a second step reaction is fed 10 to a molten resin supplied from the first extruder for performing reaction and/or devolatilization, and equipment connecting a resin discharge port 6 of the first extruder and a second extruder material supply port 7 together. A temperature Q of an extruder highest temperature portion in the first extruder and/or the second extruder is set to 180-320°C, and a reaction time t is set to 0.2-60 minutes.