This internal pressure loading system includes an internal pressure loading device and an information processing device. The internal pressure loading device is set at an inner face of a pipe, and includes a load meter which detects the load applied to the inner face of the pipe and a displacement meter which detects the deformation amount of the pipe. When the internal pressure loading device is expanded so as to increase the load to be detected by the load meter, the width of the pipe at which the displacement meter is located is reduced. On the basis of the load detected by the load meter and the deformation amount detected by the displacement meter, the information processing device evaluates the remaining strength of the pipe.