A construction method for 3D micro/nanostructure, comprising: Step (1), fixing and vacuuming a material source on a substrate; Step (2), focusing an electron beam to ensure that a position of a focus is 0-100 nm away from a surface of material source, and an interface local domain including the focus of electron beam and surface atoms is formed; and Step (3), controlling the focus of electron beam to move point by point according to a shape of a designed 3D micro/nanostructure, and realizing the construction of 3D micro/nanostructure. This disclosure realizes real-time construction of 3D micro/nanostructure through the migration of atoms driven by uneven atomic density and electric potential difference in interface local domain. This disclosure promotes integrative development of nanotechnology and 3D printing and has good value of application and promotion.