Under loading apparatus and refractory material test loading and unloading method based on same

The invention relates to an under loading apparatus and a refractory material test loading and unloading method based on the same. The under loading apparatus comprises, from bottom to up, a metal pressure bar, a spherical surface connector link, a lower pressurization rod, an upper pressurization rod, and an upper pressurization rod fixing seat which are coaxially arranged in sequence. The outside of the metal pressure bar is provided with a sliding shaft sleeve used for guiding. The spherical surface connector link includes a link seat, a spherical surface support seat, a pressurization rodconnection seat and a supporting spring, wherein the top part of the pressurization rod connection seat is in fixed connection to the lower pressurization rod; the supporting spring is arranged between the pressurization rod connection seat and the metal pressure bar, the metal pressure bar, the spherical surface connector link, and the lower pressurization rod form an under loading assembly capable of performing vertical