CONTEXT: Canal scheduling is critical for agriculture in arid and semi-arid regions. However, water delivery timing across the crop growth cycle is often overlooked, and its integration with water allocation and biomass-based bioenergy remains insufficiently addressed. OBJECTIVE: This study aims to develop a canal scheduling optimization framework that integrates irrigation timing and water allocation over the full crop growth cycle within the WEF nexus, allowing coordinated management of bioenergy, water use potential, and crop productivity. METHODS: Canal scheduling was formulated as a multi-objective optimization problem to maximize straw bioenergy potential and water productivity while minimizing water conveyance losses. The optimization was coupled with the EPIC crop growth module, which generated daily biomass growth and yield formation estimates to adjust irrigation timing and allocation across the full crop growth cycle. It was solved using the self-adaptive multi-objective differential evolution (SaMODE) algorithm under different hydrological conditions and irrigation round settings to identify robust scheduling strategies. RESULTS AND CONCLUSIONS: Application to the Huangyang Irrigation District in northwest China demonstrates that the proposed framework improves system performance primarily through optimized irrigation timing. Compared with conventional scheduling, the optimized framework reduced total water consumption by 5% and improved bioenergy potential and water productivity by 2.03% and 5.26%, respectively, while maintaining crop yields, with irrigation duration reduced by about one third. The results reveal clear trade-offs within the WEF nexus: bioenergy potential and water productivity increase simultaneously but are constrained by rising conveyance losses. Adaptive canal scheduling proves critical, as increasing irrigation rounds stabilizes yields under water-scarce conditions. Optimal irrigation timing starts around 40 days after spring recharge and ends near maize tasseling. In addition, irrigation water use shows a threshold, ranging from 3.41 & times; 107 m3 in wet years to 4.11 & times; 107 m3 in dry years. Beyond this threshold, additional water allocation yields diminishing returns. SIGNIFICANCE: The proposed framework advances canal scheduling by explicitly incorporating irrigation timing derived from crop growth dynamics and linking it with multi-objective optimization. It provides a systematic tool