A vertically mounted and magnetically driven power generation apparatus includes a transmission mechanism vertically mounted in a support frame with a spindle thereof connected with a power generator. Multiple magnetic drive assemblies are respectively mounted inside multiple shelves of the support frame. By virtue of magnetic repulsion between the magnetic drive assemblies and multiple magnetic driven members mounted on the transmission mechanism, the spindle can be vertically and suspendedly rotated within the support frame. The power generation apparatus further includes multiple magnetically stabilizing modules that provide radial or axial magnetic repulsion to the transmission mechanism so as to reduce left-and-right swing or up-and-down vibration when the spindle is rotated within the support frame. Accordingly, the power generation apparatus can achieve superior stability and optimal power generation efficiency upon high-speed operation.