The invention relates to a set of variable-temperature microscopic magnetic photoelectric testing system with flexible measuring geometry, which comprises a titanium-doped sapphire laser as well as a chopper, a wide waveband linear polarizing film, a photoelastic modulator, a first wideband depolarization beam splitting prism, a second wideband depolarization beam splitting prism, a first objective lens and a liquid nitrogen Dewar which are arranged on the emergent light path of the titanium-doped sapphire laser in sequence, wherein the refracted light path of the second wideband depolarization beam splitting prism also comprises a camera and a display connected with the same, a second object lens is arranged on the light path behind the camera, and a monochromator and a matched detector are connected behind the second object lens through optical fibers; the chopper is connected with a controller; the photoelastic modulator is connected with a controller; the refracted light path of the first wideband depolarization beam splitting prism also comprises a lighting source and a detector; the refracted light path of the second wideband depolarization beam splitting prism also comprises the camera and the display connected with the camera; a neodymium iron boron permanent magnet is coaxially sheathed on the front end of the liquid nitrogen Dewar in a contactless mode; and the system also comprises a DC current source, and two output ports of the DC current source are connected with a sample through conducting wires.