Trace elements in crops can affect the bioavailability of Se. To investigate the effect of trace element on Se bioavailability, trace element concentrations and Se bioavailability in crops from Se-rich area (Langao County, China) were analyzed using the physiologically-based extraction test (PBET) digestion model. Vegetables (rapes, radishes, and potatoes) had higher concentrations of total and bioavailable Se compared to grains (corn, rice, and sweet potatoes), suggesting they are more effective for Se supplementation. The bioavailability of Se was higher in the intestinal phase than in the gastric phase. Trace elements were positively correlated with the increased bioavailability of Se in corn, potato, and rape. Fe was a key element in increased bioavailability of Se in the gut model. Therefore, trace elements, particularly Fe, in crop can enhance Se bioavailability, suggesting their potential use in Se supplementation. The findings of this study provide valuable insights for dietary interventions to Se deficiencies.