Disclosed herein is an implant device for osseointegration to endure weight. This implant device includes an insert-type implant inserted into an amputated end of a thighbone or a lower leg bone of a leg of a patient; a load dispersing adaptor having a cap shape, encompassing both the implant and the amputated end of the leg simultaneously at a lower end of the implant; a load support plate having a plate shape, coupled with the lower surface of the adaptor, whose diameter is widened, on which a plurality of muscle fixing holes are dispersedly formed; and a coupling screw, which couples the load dispersing adaptor with the insert-type implant at a bottom of the load dispersing plate through screw-coupling.