The invention provides a 
visual test device for a damaged form of a 
pile-soil contact surface of a specially-shaped 
pile and a use method. The test device comprises a bearing platform, a model 
pile, a model tank, a water bath tank, a 
temperature control system, a 
laser source and a 
digital camera device, wherein the model pile is arranged as a full-scale specially-shaped pile and is arranged in the model tank; transparent soil is arranged on the periphery of the model pile; the model tank is arranged in the water bath tank; a rotating shaft hole is formed on the bottom of the model tank while a rotating shaft is arranged in the model tank; the rotating shaft is used for driving the model pile to generate 
vertical displacement or torsional displacement; the 
temperature control system is matched with the water bath tank and is used for adjusting the temperature of the pile-soil contact surface; and the 
laser source and the 
digital camera device are arranged on the upper side and side wall of the model tank. According to the 
visual test device provided by the invention, the 
visual observation for shear deformation of 
concave surface of the cross section of the specially-shaped pile can be realized; the shearing damage characteristics of different loading 
modes, different temperatures and different piles can be compared; the 
visual test device has significance in research on shearing of the contact surface of the full-
scale model pile; the visual test device provided by the invention has the advantages of simple structure, convenience in operation, easiness in realization and lower cost.