In order to explore the way of rational utilization of soil and water resources in coastal reclamation area, the feasibility of improving saline soil and water for irrigation with biochar was studied. A pot experiment was carried out in the soil of Jiangsu Yancheng reclamation area. By setting up the different soil biochar contents (0 and 5%) with three kinds of salinity (1g/L, 3g/L and 5g/L) in three growth stages (seedling, jointing and male stage, filling period), the cycle irrigation of fresh and saline water (“saline fresh fresh”, “fresh saline fresh” and “fresh fresh saline”) were carried out. The effects of biochar amendment and cycle irrigation on soil salt distribution and physiological growth of Maize (Zea mays L.) at different growth stages were studied. The results were as follows: maximum biochar Na+ adsorption was found at the highest salinity level. Under the three cycle irrigations of fresh and saline water, the salt content in the upper soil of 5% biochar treatment was significantly lower than that of the 0 biochar treatment. At the same time, the salt content in the lower layer was increased greatly, indicating that the biochar could alleviate the salt accumulation of surface soil and promote the soil salt moving to deep layer. The saline water irrigation reduced the maize photosynthesis capability parameters and chlorophyll content, because the salt resistance of maize was relatively weak in the nutrition stage, its inhibition was more obvious than that in the reproductive stage, while the treatment of biochar improved the photosynthetic parameters and chlorophyll content in all growth stages, and the favorable effect was especially significant in 5g/L saline water treatment. The plant height and leaf area of maize plant were decreased greatly and the maize growth was limited obviously under the “fresh saline fresh” alternate irrigation. Meanwhile, the amendment of biochar had a better gain effect on the plant height and leaf area of maize plant. The amendment of biochar improved the water condition of crops and mitigated the ion toxicity caused by salt stress. The leaves of maize showed lower leaf water potential and Na+/K+. The cycle irrigation method of “saline fresh fresh” and “fresh saline fresh” was not beneficial to the growth of maize, resulting in a significant decrease in the dry matter and yield index; the biochar amendment effectively reduced the stress effect of saline irrigation and promoted maize growth, thus enhancing the efficiency of cycle irrigation with fresh and saline water. In conclusion, the addition of biochar into soil was beneficial to land reclamation in coastal reclamation area, effectively controlling soil salinity and inhibiting soil secondary salinization. Furthermore, biochar can also improve the feasibility of cycle irrigation with saline water. Biochar mitigated the effect of salt stress in the sensitive period of crops due to its adsorption ability, reduced production loss and improved the saline water use efficiency. The research result can provide scientific basis and theoretical support for the rational development and utilization of saline water and the sustainable development of agriculture in coastal reclamation area.