A wire grid structure and a manufacturing method therefor, and a projection screen are provided. The manufacturing method includes: extruding a molten mixed material body in a melt extruder to a casting roll to form a casting piece; patterning the casting piece by means of an impression roll to form a precursor having a preset wire grid structure pattern, where the precursor is wound on the impression roll and has a first dimension in a height direction; stretching the precursor by a first group of stretching rolls and a second group of stretching rolls in two opposite directions along a direction perpendicular to the height direction to form the wire grid structure, a preset distance being configured between the first group of stretching rolls and the second group of stretching rolls. The wire grid structure has a second dimension in the height direction that is greater than the second dimension.