Context or problem: Saline water irrigation alleviates freshwater scarcity in arid and semi-arid regions but causes salt stress. However, the mitigating effects and regulatory mechanisms of organic fertilizer on salt stress remain unclear. Objective or research question: This study aimed to clarify the growth and development responses of wheat and maize under saline water irrigation combined with organic fertilizer application, and to reveal the distinct mechanisms affecting these two crops. Methods: The four electrical conductivity (EC) levels of irrigation water (1.3 dS center dot m- 1, T1; 3.4 dS center dot m- 1, T2; 7.1 dS center dot m- 1, T3; 10.6 dS center dot m- 1, T4) and two fertilization types of organic fertilizer application (F1) and no organic fertilizer application (F0) were set up in the experiment. During the 2022-2024 growing periods, plant height (PH), leaf area index (LAI), dry matter accumulation (DMA), net photosynthetic rate (Pn), transpiration rate (Tr), chlorophyll relative content (SPAD), and yield of winter wheat and summer maize were measured. Results: The results showed that winter wheat exhibited significant reductions in PH, LAI, DMA, Pn, Tr, and SPAD under T4 compared with T1. In contrast, summer maize showed significant decreases in growth and physiological indicators under both T3 and T4, demonstrating its greater sensitivity to saline water irrigation. F1 effectively mitigated the adverse effects of saline water irrigation on wheat and maize growth, enhancing the productivity of wheat-maize system. Especially under T3 and T4 treatments, the F1 led to an increase of 9.36 % and 12.75 % in the average annual yield of wheat, and by 9.03 % and 8.44 % for maize, respectively. Furthermore, organic fertilizer application elevated the EC thresholds of irrigation water for 5 % and 10 % yield reductions in the wheat-maize system under saline irrigation. Partial least squares path modeling (PLS-PM) indicated that organic fertilizer enhanced yield through crop-specific pathways. For winter wheat, organic fertilizer enhanced yield through the combined improvement of growth indicators as well as photosynthetic performance. Whereas summer maize primarily regulated its growth through photosynthesis to promote yield, with no significant direct impact of organic fertilizer on growth indicators. Conclusions: In summary, organic fertilizer application mitigated the negative effects of saline water irrigation and boosted productivity in both types of crops through different pathways. Implications or significance: The research provided a scientific basis for sustainable grain production under saline water irrigation.