Precise micrometer measuring tool used for large precision equipment alignment and measuring method thereof

The invention discloses a precise micrometer measuring tool used for large precision equipment alignment and a measuring method of the precise micrometer measuring tool. The measuring tool comprises a special box staff which is of a hollow cylinder shape and provided with millimeter scales and a micrometer head which is of a hollow cylinder shape and provided with a window opening in the front face. The position of the window opening in the front face of the micrometer head is provided with a small graduated scale, the upper end and the lower end, symmetrically arranged on the two sides of the radical center, of the micrometer head are respectively provided with a pair of positioning screws, and a fixing screw is arranged between the two positioning screws on the one side of the micrometer head. Sliding trenches are symmetrically arranged on the two sides of the radical centre of the special box staff, wherein the width of the sliding trenches conforms to the diameter of the positioning screws on the micrometer head. The precise micrometer measuring tool has the advantages of being easy to operate, convenient to carry, reliable in the measuring effect and free of precision level which is expensive in price and complex in operation and an indium steel ruler to be matched with the micrometer measuring tool in the measuring process, and therefore the construction expenses are reduced and the construction cost is lowered.