A stack-assembly-type apparatus for supporting a formwork, the stack-assembly-type apparatus comprising: an upper and a lower support frame, each comprising a front vertical frame positionable at a rear surface of the formwork, a rear vertical frame positioned at rear of the front vertical frame, and a connection frame connecting the front vertical frame to the rear vertical frame in a square form; front and rear pipe fixing parts (40 and 50) configured to couple and assemble at least one further support frame provided in parallel in left and right directions to front and rear connection pipes (200 and 200') provided in left and right directions at front and rear portions of the support frame; and front and rear vertical assembling parts (60 and 70) configured to connect and assemble the upper and lower support frames to each other by vertically stacking the support frames, wherein, in the front vertical assembling part, a connection part is located on an upper portion of the front vertical frame and extends upward higher than an upper end of the rear vertical frame, and left and right brackets (61, 61') are connected to a lower front of the connection frame and extend in the left and right direction at a lower portion of the front vertical frame, and the left and right brackets (61 and 61') of the front vertical assembling part are connected to the front of the connection frame at an inclination by an inclination part of each left and right bracket (61, 61'), whereby the front vertical assembling part comprises further an assembly part comprising an inclination surface corresponding to the inclination part of each of the left and right brackets (61, 61') and a coupling hole located perpendicularly to the inclination surface, the assembly part is securely provided on the upper portion of the front vertical frame, whereby the upper and lower support frames are connected to each other by the assembly part of the front vertical assembling part of the lower support frame inserted between the left and right brackets (61 and 61') of the front vertical assembling part of the upper support frame, and by a fastening screw rod that is supported such that an upper end thereof is blocked to upper ends of the left and right brackets (61 and 61') of the front vertical assembling part of the upper support frame by a support washer, and which fastening screw rod is screw-coupled to the coupling hole of the assembly part of the lower support frame, so that the front vertical assembling parts of the upper and lower support frames are vertically fixed. an upper and a lower support frame, each comprising a front vertical frame positionable at a rear surface of the formwork, a rear vertical frame positioned at rear of the front vertical frame, and a connection frame connecting the front vertical frame to the rear vertical frame in a square form; front and rear pipe fixing parts (40 and 50) configured to couple and assemble at least one further support frame provided in parallel in left and right directions to front and rear connection pipes (200 and 200') provided in left and right directions at front and rear portions of the support frame; and front and rear vertical assembling parts (60 and 70) configured to connect and assemble the upper and lower support frames to each other by vertically stacking the support frames, wherein, in the front vertical assembling part, a connection part is located on an upper portion of the front vertical frame and extends upward higher than an upper end of the rear vertical frame, and left and right brackets (61, 61') are connected to a lower front of the connection frame and extend in the left and right direction at a lower portion of the front vertical frame, and the left and right brackets (61 and 61') of the front vertical assembling part are connected to the front of the connection frame at an inclination by an inclination part of each left and right bracket (61, 61'), whereby the front vertical assembling part comprises further an assembly part comprising an inclination surface corresponding to the inclination part of each of the left and right brackets (61, 61') and a coupling hole located perpendicularly to the inclination surface, the assembly part is securely provided on the upper portion of the front vertical frame, whereby the upper and lower support frames are connected to each other by the assembly part of the front vertical assembling part of the lower support frame inserted between the left and right brackets (61 and 61') of the front vertical assembling part of the upper support frame, and by a fastening screw rod that is supported such that an upper end thereof is blocked to upper ends of the left and right brackets (61 and 61') of the front vertical assembling part of the upper support frame by a support washer, and which fastening screw rod is screw-coupled to the coupling hole of the assembly part of the lower support frame, so that the front vertical assembling parts of the upper and lower support frames are vertically fixed.