A bearing system for rock mechanics test under high temperature and high pressure multi-field coupling includes a force sensor lifting seat and a jack. The force sensor lifting seat includes a connecting disk connected with the jack, a support disk, and an operation channel. A groove dented downwards is arranged on the connecting disk, the support disk is disposed in the groove and freely propped upon the connecting disk; through holes of the connecting disk and the support disk form a control operation channel; and a limiting device is arranged for preventing an MTS triaxial force sensor from disengaging from the support disk. A bolt hole of the force sensor can be aligned with a mounting hole on a solid steel column by rotating the connecting disk for convenient and accurate bolting.