This study analyzes the safety of a seawall slope armor based on the reliability theory. By taking a typical slope-type seawall in Guangdong Province as an example to establish a performance function for the slope armor panel, we first calculate the probability of panel failure under the existing conditions and then conduct a sensitivity analysis of factors such as wave height, period, water depth, and plate thickness. The results of this study can provide a technical reference for the design, construction management, and operation and maintenance of the armor structure for similar seawalls in the future.