The technology of submarine sediment resistivity measurement is widely used in such as the marine geological survey, the marine environment research. A resistivity measurement system was developed in the platform of in-situ measurement which based on seafloor drilling machine. In order to precision manage the weak voltage signal which outputted by the resistivity probe, the cross-correlation algorithm theoretical was derivated and MATLAB simulation was carried out. Finally the software was transported in TMS320F28069 DSP processor and hardware was designed . A Mass of contrast experiment shows that the cross-correlation detection is an effective way to process weak signal. It can not only improve the submarine sediment resistivity instrument’s accurate, but also improve the anti-jamming ability.