The invention discloses a sharp curved tunnel model tester and a method thereof and aims at exploring stratum load effect changes and providing corresponding reasonable proposals to important parameter selection and engineering disaster avoidance of a sharp curve shield tunnel during actual design construction. In order to achieve the design purpose, the sharp curved tunnel model tester mainly comprises the following components including a sand tank, a shield simulation machine and a ground surface settlement monitoring system; the sand tank is used for being filled with a soil layer for a simulation test inside; a plurality of settlement observation points are laid on the surface of the soil layer; the shield simulation machine comprises a shell with different curvatures and a motor drivesystem to simulate implementation of shield operation in the sand tank; the ground surface settlement monitoring system comprises a laser displacement sensor to perform ground surface settlement datamonitoring in the excavation process of the shield operation, obtain a corresponding relationship between soil layer settlement and the sharp curved tunnel curvature and provide guidance to subsequent field construction.