Using fog droplet spectrum data in Xiangan from 2019 to 2021, We investigated the statistical characteristics of micro-physical parameters and fog droplet spectrum of sea fog in Southern coast of Fujian. Based on the relationship between visibility and particle number concentration(N), liquid water content(L) of fog and relative humidity(RH), We established various parameterization schemes and evaluated the fitting effect of each scheme. The results showed that average N and L of sea fog in Southern coast of Fujian was 47.5 cm-3 and 0.0763 g·m-3. N and L increased significantly with the enhancement of fog level while mean diameter, effective diameter increased slowly. When visibility drop below 100 m, average N and L reached 115.42 cm-3 and 0.228 g·m-3. N and L spectrum both exhibited double peak characteristic. Main peak of N located in 4～6 μm and secondary peak was in 22～26 μm. L showed opposite characteristic with peak value in 24～26 μm and secondary peak in 4～6 μm. This showed that N of fog is mainly controlled by small droplets, but particles of 20～30 μm contributed more to L. Compared with other coastal regions, average N of Southern coastal Fujian was smaller than southern coast of China but larger than eastern coast of China. Average L was larger than southern coast but smaller than eastern coast. Compared with inland regions such as city or country sites, N of the same fog level was smaller but L was larger. Four parameterization schemes of visibility were established by using full samples and segmented method. Test results indicated that visibility subsection fitting scheme based on L×N was optimal, especially for visibility below 1 km .