A mounting device with an anti-drop function comprises a seat body (1) and a main bracket (2). The seat body (1) is detachably mounted on the main bracket (2) by means of a plug positioning structure. The seat body (1) and/or the main bracket (2) are provided with an anti-drop device for preventing the seat body (1) from falling off the main bracket (2). A stage lighting optical device comprises an optical assembly and the mounting device as mentioned above, wherein the optical assembly is mounted on the seat body (1) of the mounting device, and the main bracket (2) of the mounting device is fixed on a stage lighting main body. This invention is simple in structure and convenient for use, can solve the problem that the pluggable optical components in the stage lighting are easy to fall off, and can achieve the effect of easy plugging and drawing.
