The invention relates to the technical field of instruments, in particular to an instrument housing. The instrument housing comprises a hollow cylindrical housing body, a glass lens and a rotary sleeve, wherein a slot body is formed in the side surface of the hollow cylindrical housing body; a lens holder is arranged at a position, which is correspondingly located below the slot body, on the inner circumferential surface of the hollow cylindrical housing body; the glass lens is circular; the outer diameter of the glass lens is equal to the inner diameter of the hollow cylindrical housing body; the glass lens is arranged on the lens holder inside the hollow cylindrical housing body; an external thread is formed on the outer circumferential surface of the hollow cylindrical housing body; the rotary sleeve is arranged outside the hollow cylindrical housing body in a sleeving manner; an internal thread is formed on the inner circumferential surface of the rotary sleeve; the external thread is matched with the internal thread; and multiple convex parts are arranged on the circumferential surface of the rotary sleeve. The instrument housing is simple in structure; and by rotation of the rotary sleeve, the slot body can be exposed, and the glass lens can be taken out, so that the hollow cylindrical housing body does not need to be disassembled, and the operation is convenient.