A flow deflector, an inkjet printing method, an inkjet printing device, and a method for manufacturing a display substrate are provided. The flow deflector includes a plate-shaped body, and the plate-shaped body includes a first surface and a second surface opposite to each other, a plurality of through holes is arranged in the plate-shaped body, each of the plurality of through holes penetrates from the first surface to the second surface, and comprises a first opening formed on the first surface and a second opening formed on the second surface, and an opening area of the first opening is larger than an opening area of the second opening.