An embodiment of the invention provides a micrometer CT rock core pretreatment method and device. The method includes the steps: placing a rock core sample into a metal straight pipe, and enabling thelower end of the rock core sample to extend out of the lower end of the metal straight pipe; taking the lower end surface of the metal straight pipe as a tangent plane, and cutting off the lower endof the rock core sample extending out of the metal straight pipe, placing a carbon rod with the diameter as same as that of the rock core sample into a storage cylinder, and enabling the upper end ofthe carbon rod to extend out of the upper end of the storage cylinder; taking out the rock core sample from the metal straight pipe, and bonding the lower end of the rock core sample and the upper endof the carbon rod in an aligned manner; moving the storage cylinder upwards, and enabling the carbon rod and the rock core sample to be placed into the storage cylinder; standing for set time, and moving the storage cylinder downwards to take out a bonding body of the carbon rod and the rock core sample. The outer diameter of the metal straight pipe is matched with the diameter of the rock core sample, the lower end surface of the metal straight pipe is a horizontal plane, the storage cylinder can vertically move relative to the carbon rod, and the upper end surface of the carbon rod is a horizontal plane. The pretreatment method can ensure that a prepared sample is vertical and is convenient to operate and easy to implement.