Selenium-enriched wheat is a viable strategy to address dietary selenium deficiencies in selenium-deficient regions. To explore the selenium uptake, translocation, and distribution patterns in various wheat tissues, a wheat line Chuanwen 2401 was used as the material. Four foliar spraying treatments were set up: three nano-selenium application rates of 7.5 g·hm^-2 (C₁), 15.0 g·hm^-2 (C₂) and 30.0 g·hm^-2 (C₃), with clean water as the control (CK), to analyze the effects on selenium absorption and translocation, selenium speciation in grains forms, nutrient element contents, ecological risks, dietary selenium intake, yield and yield components. The results showed that, foliar nano-selenium spraying significantly increased selenium content in various wheat tissues, and selenium content in wheat grain significantly increased by 25.5-126.8 fold. Compared with CK, selenium translocation coefficients showed significant changes, for example, TF of flag leaf and the 1st stem node, the 2nd leaf and 2nd stem node, the 3rd leaf and 3rd stem node, and the 4th leaf and 4th stem node were significantly reduced by 85.5%-91.3%, 64.7%-82.4%, 75.0%-75.0%, and 50.0%-83.3%, respectively. TF of rachis and glume, rachis and grain were significantly increased by 209.4%-718.8% and 111.4%-640.0%, respectively. Only selenocysteine (SeCys) and selenomethionine (SeMet) were detected in CK grains, with SeCys accounting for the higher proportion. An additional selenium speciation, methylselenocysteine (MeSeCys), was identified in grains under C₁, C₂, and C₃ treatments, with SeMet being the dominant selenium form. Compared with CK, contents of Mn, Zn, Cu, and grain protein significantly decreased by 12.7%-15.6%, 4.1%-18.2%, 6.8%-16.1%, and 6.9%-22.7%, respectively. Fe content significantly increased by 46.4%-111.1%. The ecological risk index (Er) of the C₁ treatment was 51.6, which was closest to the safety threshold (40.0), and the estimation of daily selenium intake (EDI) was 297.2 μg, falling within the recommended range (60-400 μg). The Er value of CK was within the safety threshold, but its EDI was far below the lower limit of the recommended range. Both Er and EDI values of C₂ and C₃ treatments exceeded the safety/recommended ranges. Compared with CK, yield thous and graiin weight of C₁, C₂, and C₃ treatments significantly increased by 3.5%-8.5% and 2.8%-4.4%, respectively. Effective spikes and grains per spike showed no significant changes. In conclusion, foliar nano-selenium spraying significantly increased the selenium content and yield of wheat grains, and improved the wheat grains quality by regulating the selenium speciation, proportion, and nutrient element content. Among them, C₁ treatment (7.5 g·hm^-2) was the optimal foliar nano-selenium spraying concentration.