Disclosed is a driving method of a wheelchair power apparatus for electronic driving conversion. It is an object of the present invention to provide a wheelchair power apparatus for electronic driving conversion, which can provide severely disabled people, for instance, patients with spinal cord injury, the weak or the old, who use wheelchairs, with convenience in movement, and convert a manual four-wheel wheelchair into an electronic three-wheel wheelchair just by detachably mounting the electronic module having electronic wheels to the existing manual four-wheel wheelchair.