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As one of the three major saline-alkali regions worldwide, the Songnen Plain is characterized by heavy soda saline-alkali soil. When designing and optimizing agricultural implements for this unique soil type, it is essential to consider soil tillage resistance. The discrete element method (DEM) has become a crucial tool for optimizing tillage machinery due to its precision and efficiency in predicting soil tillage resistance. A DEM model specific to soda saline-alkali soil and performs parameter calibration was established, laying the foundation for the development of equipment for the improvement and utilization of saline-alkali soil. The Hertz-Mindlin with Bonding V2 model was selected as the DEM simulation framework. Intrinsic parameters for soil and implements were derived from the literature, while an inclined plane test was used to determine contact parameters between soil particles and between soil and implements. Further, the optimal Bond parameters were identified through cone penetration and uniaxial compression tests, combined with central composite design (CCD). Finally, field tests validated the accuracy of the calibrated parameters. Results showed that the yield resistance of soil in cone penetration and uniaxial compression tests was 153.3 N and 331.4 N, respectively, while tillage resistance of the furrow opener at depth of 40 cm was 11 907.5 N. The optimal Bond parameter combination was determined to be normal stiffness per unit area Kn=3.68×107 N/m3, tangential stiffness per unit area Ks=2.97×107 N/m3, normal stress σ=197 374 Pa, and tangential stress τ=96 285.5 Pa. By comparing the predicted and actual resistance values from cone penetration tests, uniaxial compression tests, and field tests, discrepancies of -0.95%, 0.78% and -8.61% were observed, respectively. The reliability of the DEM model was confirmed, demonstrating its proficiency in accurately predicting the tillage resistance of sodic saline-alkali soils.