The invention discloses a loading and connecting structure for full scale tests of an extended foundation. The loading and connecting structure comprises a loading device, wherein the loading device is a hydraulic static pile pressing machine; a force transmitting concrete pile is clamped by a vice jaw of the loading device; short pillars are arranged under the force transmitting concrete pile; a bracket pillar is fixed to the side surface of each of the short pillars; the bracket pillars take the shape of right-angled trapezoids, wherein the lower bottom of each of the bracket pillars is connected with the side surface of the corresponding short pillar; right-angled waists of the bracket pillars and the upper end surfaces of the short pillars are positioned on the same horizontal surface; embedded parts are connected to the upper parts of the short pillars and the upper parts of the bracket pillars; a pressure sensor is arranged in each of the embedded parts; the pressure sensors are in external connection with a pressure measuring instrument. According to the loading and connecting structure disclosed by the invention, the bracket pillars are arranged on the side surfaces of the short pillars, so that the loading device not only can perform shaft center loading for the extended foundation, but also can perform eccentric loading; a reaction frame jack system is replaced by the hydraulic static pile pressing machine, so that the experiment efficiency of the full scale tests against the extended foundation of a high width-to-height ratio is effectively improved, the cost is saved, and the time is shortened.