In order to study the effects of different application modes of biochar on water and salt regulation in saline alkali soil and wheat seedling growth, an indoor bucket planting simulation experiment was conducted. Biochar was covered on the surface of the soil in two forms of powdery and rod-shaped, with a mass percentage of 1%, 3% and 5%. Under the same treatment, biochar was mixed with 10 cm of the soil surface, and the treatment without biochar was used as a control (CK). The results showed that under the condition of "dry sowing and wet emergence", the emergence rate of wheat treated with FF (powdery cover) and GF (rod-shaped cover) was 7.33 to 9.00 and 3.00 to 3.33 times higher than that of CK, respectively. The emergence rate of FH and GH treatments increased by 66.67% to 166.67% and 33.00% to 367.00%, respectively, compared with CK. The plant height of FF and GF treatments significantly increased, with an increase of 21.52% to 34.55% and 24.54% to 40.48%, respectively, compared with CK. The plant height of FH and GH treatments increased slightly, with an increase of -1.35% to 12.22% and 3.76% to 8.59%, respectively, compared with CK. There were significant differences in post irrigation moisture content among different application modes, and FF treatment increased the surface soil moisture content by 0.31% to 15.58% compared with CK. The surface soil moisture content treated with GF decreased by 0.40% to 7.65% compared with CK. The soil moisture content of FH and GH treatments increased by 7.33% to 18.61% and 1.33% to 18.38%, respectively, compared with CK. After evaporation, the moisture content of FF and GF treatments increased by 4.34% to 45.38% and 27.08% to 53.22%, respectively, compared with CK. After evaporation, the moisture content of the 0-15 cm soil layer increased significantly. The soil moisture content of FH and GH treatments increased by 3.26% to 16.66% and 5.77% to 36.37%, respectively, compared with CK. The maximum relative change rate of conductivity in the 0-10 cm soil layer of CK was 124.76%, while that in FF and GF treatments was 59.61% to 114.73% and 18.21% to 86.47%, respectively. The relative change rate in conductivity of GH and FH treatments was 67.26% to 96.30% and 72.05% to 122.32%, respectively. Compared with CK, the evaporation of FF and GF treatments decreased by 0.76% to 27.21% and 53.49% to 77.02%, respectively. Compared with CK, the evaporation of FH and GH treatments decreased by 1.95% to 4.79% and 1.71% to 14.82%, respectively. The improvement effect of biochar depended on the amount and the application method of biochar. Under equal carbon input conditions, FF and GF treatments had better effects on water and salt distribution, inhibition of evaporation, and crop growth than FH and GH treatments, which could be used as suitable models for adding biochar to improve saline alkali land in arid areas.