[Objective] Five types of biochar were prepared by corn straw and sludge at different temperature, the effects of different biochar applications on basic soil physical and chemical properties were examined to provide scientific basis for the improvement of saline alkali soil and the ecological restoration of soil pollution.[Methods] Five types of biochars were prepared by corn straw and sewage sludge at the temperatures of 300,350,400,450,500℃, the structure and properties of biochars were characterized by scanning electron microscope(SEM), element assay and fourier transform infrared spectroscopy(FTIR). A laboratory incubation study was conducted to examine the effects of biochar on the basic physical and chemical properties in saline soil.[Results] The element C content increased and the elements O, H, N gradually reduced when temperature increased. With the increase of biochar, the content of organic carbon in the saline soil was significantly improved; while the mineral nitrogen, phosphorus, available phosphorus and available potassium changed very little; the content of CEC in the saline soil was significantly improved, the pH value was slightly lower, the content of soluble salts decreased significantly.[Conclusion] Corn straw and sludge-based biochar can improve the saline soil nutrient content and fertility index, and can reduce the soil salt. Corn straw and sludge-based biochar can be used for the improvement of saline soil.