The structural, magnetic, and electronic properties of Fe82Si4B10P4 metallic glass were systemically investigated by theoretical simulations. Strong atomic interaction between Fe and metalloid atoms can be observed, while the direct metalloid-metalloid atomic bonds are rare due to the solute-solute avoidance effect. The calculated value of saturation magnetic flux density (B S ) is ~1.65 T, approaching to experimental result, which is contributed by not only the electron exchange between Fe and metalloid atoms, but also the p-d orbital hybridization of Fe atoms. Moreover, Fe atoms with neighboring P atom behaving larger magnetic moments reveals the important role of P element for promoting the B S value. The potential correlation between magnetic behaviors and the local atomic packing in this study sheds some light on the structural origin of the soft magnetic properties and, thereby the theoretical guidance for the development of new soft-magnetic metallic glasses.