The invention discloses an adjustment device for four-knife slits in optical experimental equipment. The adjustment device comprises a clamping part, as well as a guide rail module, an adjustment module and a rotating module, wherein the clamping part is connected with the four-knife slits, the guide rail module is used for controlling the movement of the clamping part in a horizontal direction, the adjustment module is used for controlling the movement of the clamping part in a vertical direction, and the rotating module is used for controlling the circumferential rotating of the clamping part; and the guide rail module consists of a lower substrate, a rotating shaft and an upper substrate which can move leftward and rightward along the lower substrate under the driving of the rotating shaft, a mounting seat is arranged on the upper substrate, and the clamping part is arranged on the mounting seat. According to the adjustment device, the four-knife slits can be adjusted from all directions, the adjustment is convenient and fast, the adjustment precision is high, the stability is good and the structure is simple.