For the health monitoring of the offshore drilling platform in the salt-fog environment, three nonmetallic materials, i.e., silica, FR-4 epoxy board and sheet molding compound (SMC), with the good anti-corrosion ability were chosen as the packaging materials for the fiber Bragg grating (FBG) strain sensors. By selecting a highly sensitive structure of the fiber Bragg grating strain sensor, the performances of the sensors with three materials were investigated both numerically and experimentally. The strain sensitivities were 3.76 pm/με, 3.02 pm/με and 3.03 pm/με, respectively. The linearity was better than 0.998. It provides useful information for developing sensors for the marine engineering.