An optical fingerprint sensor apparatus and an assembling method thereof are provided. The optical fingerprint sensor apparatus includes: a support frame structure having an opening therein, the opening penetrating through the support frame structure; an optical fingerprint sensor module disposed in the opening; a support plate disposed below the optical fingerprint sensor module and at the bottom of the support frame structure, wherein the support plate is fixedly connected to the bottom of the support frame structure; an elastic support member disposed between the optical fingerprint sensor module and the support plate, wherein the elastic support member is fixedly connected to the optical fingerprint sensor module and the support plate, respectively; and a self-luminous display panel disposed on the optical fingerprint sensor module and the support frame structure, wherein the self-luminous display panel and the support frame structure are fixedly connected. Performance of the optical fingerprint sensor apparatus is improved.