The farmland in the Hetao Plain is facing severe challenges of salinity obstruction and water scarcity, which greatly constrain the sustainable development of agriculture in the region. To investigate the effects of mulched drip irrigation on soil properties in wide (70 cm row spacing) and narrow (50 cm row spacing) rows and crop yields of saline farmland in the Hetao Plain, a field experiment was conducted with maize as the test crop, in which two treatments were set up: drip irrigation (narrow row) with and without plastic film mulching. The results showed that drip irrigation induced significant surface accumulation of soil salinity, whereas mulched drip irrigation mitigated this phenomenon, with a significant reduction of soil salinity in narrow rows ranging from 25.29% to 56.90%, and a 15.78% increase in soil water retention capacity in the early growth stage of maize. Mulched drip irrigation increased total nitrogen and organic carbon contents in the 10~20 cm and 20-40 cm soil layers of narrow rows, and promoted the accumulation of available phosphorus and potassium in the 0-40 cm soil layer, while driving the migration of nitrate to the deeper soil layer (10-40 cm), and reducing the nitrate residues in the surface layer. Mulched drip irrigation increased soil invertase and urease activities in the 0-10 cm and 10-20 cm soil layers of the narrow rows, thereby improving soil carbon and nitrogen metabolism capacity. However, mulched drip irrigation reduced maize root parameters such as total root length, root surface area, number of branches and number of crosses, which resulted in a reduced maize yield. Therefore, this study proposes that in the Hetao Plain region, the plastic film should be removed at an appropriate time during the late stage of growth of mulched drip-irrigated maize in saline farmland to promote the development of root extension and enhance the effective recharge of soil water by rainfall, thereby achieving a synergistic effect of crop productivity enhancement and soil property improvement.