The invention belongs to the technical field of testing equipment for buildings and relates to a visual open double-wall model tubular pile testing device. An inner tube is nested in an outer tube. The lower portion of the inner tube is used as an end plate. The upper portion of the inner tube is connected with the end plate through an arc-shaped bend. An inner-outer-tube gap is formed between the outer tube and the inner tube. The top end of the outer tube and the top end of the inner tube are rigidly connected through a top plate. A gap between the bottom end of the outer tube and the bottom end of the inner tube is filled with silica gel. Wire holes are reserved in the two sides of the tops of the outer tube and the inner tube. Four sliding cushion blocks of a spherical structure are mounted in the positions, away from the top plate by 400 mm and 800 mm, between the outer tube and the inner tube at equal intervals in the circumferential direction. The sliding cushion blocks are arranged on sliding cushion block bottom supporting plates. Micro cameras are mounted in the inner-outer-tube gap. Optical fiber sensors are mounted on the inner wall of the outer tube and the outer wall of the inner tube. Micro resistance earth pressure meters are mounted at the bottom of a pile body of a model tubular pile. The visual open double-wall model tubular pile testing device is simple in structure, convenient to operate and maintain, low in cost and visual and accurate in testing result.