A method for transferring light-emitting elements onto a package substrate includes: providing a light-emitting unit including a temporary substrate and light-emitting elements; disconnecting the light-emitting elements from the temporary substrate to allow the light-emitting elements to float on a fluid; adjusting spacings between the light-emitting elements to have a predetermined size by controlling flow of the fluid; placing a package substrate into the fluid, followed by aligning the light-emitting elements with connecting pads of the package substrate so as to correspondingly place the light-emitting elements on the connecting pads; and removing the package substrate with the light-emitting elements from the fluid.