The invention provides a rod type detecting instrument fixing device with a position-adjustable cable pile hole. The cable pile hole is formed in a cable pile-hole plate, sliding ways are formed in guide rods respectively, and an opening is formed in the left end surface of each sliding way; sliders are arranged on the two sides of the top surface of the cable pile-hole plate, and the sliders are inserted into the sliding ways in a sliding mode respectively; a clamping seam is formed by the half bottoms, below the guide rods, on the left end surface of a body and a gap between the right end surface of the cable pile-hole plate; each first lug is connected with the corresponding second lug through a connecting bolt which is located above the clamping seam, the head of each adjusting bolt is located on the left side of the corresponding first lug, and a screw of each adjusting bolt vertically penetrates through the corresponding first lug and horizontally extends into the clamping seam; the inner diameter of a locking sleeve hole is smaller than or equal to the diameter of a rod body; the locking sleeve hole comprises a first half hole in the right end surface of the body, a second half hole is formed in a separate body, and the second half hole and the first half hole can form the locking sleeve hole; the body and the separate body are connected through a plurality of locking bolts.