The present disclosure discloses a mass transfer method and system for micro light emitting diodes, wherein the mass transfer method includes: providing a component substrate on which a plurality of micro light emitting diodes are formed; picking up the micro light emitting diodes on the component substrate at least once by a plurality of bonding structures on a first medium load substrate, and transferring micro light emitting diodes picked up every time to a second medium load substrate; and transferring the micro light emitting diodes on the second medium load substrate into corresponding sub-pixels on a target substrate at one time, wherein one of the micro light emitting diodes on the second medium load substrate corresponds to one of the sub-pixels on the target substrate.