As a neurotoxic environmental contaminant, perfluorooctane sulfonate (PFOS) has made a great impact on brain tissue. Neurotoxicity studies have shown that PFOS can cause abnormally high levels of calcium concentration in the hippocampus, thus inhibiting the growth of synapses, elevating the glutamate level in the nervous system, influencing behavioural response, and destroying the central nervous system, but the mechanism has not been explored by in-depth discussion. As an important second messenger in nerve cells, calcium ions mediate the release of neurotransmitters, the formation of nerve spinous process and growth through the transmission of information, and are an essential requirement for maintaining nerve physiological functions. In this paper, calcium signal transduction pathways in hippocampus cells are systematically introduced, which can help to clarify the neurotoxic mechanism of PFOS, and provide further scientific basis for learning and memory ability.