The invention relates to a fixation device for an on-line industrial pipeline thickness measuring probe. The fixation device comprises two steel belt hoops sheathed on a pipeline and a fixation clamping base fixed on the two steel belt hoops, wherein the steel belt hoop is provided with an annular hooping belt covering the outer wall of the pipeline and a locking structure used for locking the hooping belt. The locking structure is provided with a hooping belt sleeve fixed on one end of the hooping belt and a hooping buckle fixed on the other end of the hooping belt. One end of the locking structure is connected with the hooping bolt sleeve, and the other end of the locking structure is inserted into the hooping buckle to be used for locking a hooping bolt of the hooping belt. The fixation clamping base is provided with a inverted U-shaped clamping base body, probe bolts and probe nuts, wherein the probe bolts and the probe nuts are connected with the part of a flat plate of the inverted U-shaped clamping base body, and the lower parts of the probe bolts are provided with positioning pins. A clamping base slot used for clamping and placing a sensor probe is formed in the middle of the part of the flat plate of the clamping base body, and thread through holes used for installing the probe bolts are formed in the parts of the flat plate of the clamping base body on the two sides of the clamping base slot. The fixation device realizes the zero damage of the installation of the probe. Moreover, the fixation device can be conveniently disassembled or assembled, and is suitable for both high temperature and normal temperature.