A manufacturing method of a metal grid includes: providing a base substrate; forming a pattern including a first dielectric layer on the base substrate through a patterning process such that the first dielectric layer has a first groove in a lattice shape; forming a second dielectric layer on a side of the first dielectric layer away from the base substrate such that the second dielectric layer is deposited at least on a sidewall of the first groove to form a second groove in a lattice shape; and forming a metal material in the second groove, and removing at least a part of a material of the second dielectric layer such that an orthographic projection of the part of the material of the second dielectric layer on the base substrate does not overlap with an orthographic projection of the metal material on the base substrate, to form a metal grid.