The present application provides an intelligent sofa mechanical extension device, including a base, a driving component and an extension component, where the driving component and the extension component are disposed on the base. The driving component includes a motor and a motor guide rail that are disposed on the base. The motor guide rail is provided with a motor moving slider in a slidable manner. An end of the motor is connected to the moving slider. The moving slider is connected to a driving rod through a drive connector. The driving rod is disposed on the seat cushion support assemblies on the left and the right side. The extension component is driven to stretch or retract with back-and-forth movement of the motor moving slider along the motor guide rail.