The saline/sodic soil in the coastal reclamation area of Jiangsu Province was taken as the subject investigated. Based on Micro-CT scanning technology, the changes in total porosity, soil water characteristic curve and unsaturated hydraulic conductivity of saline/sodic soil after applying biochar were analyzed and the soil hydraulic properties were predicted based on fractal models. Therefore, the effects of biochar application on soil structure and hydraulic characteristics in coastal reclamation area were revealed. The surface soil (0~20cm) was amended by thoroughly mixed biochar with three levels of application rates (0, 2% and 5% by mass of soil) in a completely randomized design with three replicates for each treatment. The results showed that bulk density of soil was significantly reduced and total porosity and macroporosity of soil were increased obviously after applying 5% biochar. Besides, the proportion of waterstable aggregates with size greater than 0.25mm, the fractal dimension of soil pores was significantly increased. The saturated water content and saturated water conductivity of soil were also improved. Combined with the Micro-CT scanning technology and the fractal theory, the water characteristic curve and the unsaturated hydraulic conductivity of the improved saline/sodic soil were predicted. The accuracy of the prediction was high, which can be used in the study of practical problems.