Containment is the last barrier of Pressurized Water Reactors (PWR) Nuclear Power Plant (NPP), and its safety state is extremely important during operation. The monitoring and evaluation of the safety state of the containment requires both local high precision and large-scale integral and continuous strain monitoring. In this paper, the strain variation of a containment during the Integrated Leakage Rate Test (ILRT) was investigated by a multi-dimensional optical fiber system, which included Fiber Bragg Grating (FBG), White Light Interferometry (WLI), and distributed Brillouin Optical Time Domain Analysis (BOTDA) for local (centimeter-scale), arbitrarily length scale, and long-distance strain measurement, respectively. The results show that the system can well monitor the strain change of the containment. Specifically, the BOTDA shows the features of long sensing distance, high spatial resolution and high precision, and the WLI can monitor both the radial displacement and the strain. The multi-dimensional optical fiber system can cover the strain measurement from local point to large scale, which is a promising improvement to the existing structural health monitoring technology for the NPP containment.