The invention relates to the technical field of alignment control of pre-assembled segmental beams in bridge engineering, in particular to a method for controlling alignment of pre-fabricated segmental beams based on a short-line matching method. The method comprises the following steps: S1, performing on-site data measurement; S2, establishing a local global coordinate conversion system; S3, n-1# block 6 control point measured local coordinates are converted into measured global coordinates data; S4, deviation analysis is performed on the -1 # block; S5, determining the coupling angle of n-1 #two end axis and performing decoupling; S6, calculating the correction coordinates of the I end of the n # block; S7, judging whether the adjustment is made to the n + 1 # block; S8, judging whether there is deviation in the construction of the n # block, and if so, adjusting the positioning point of the I end section of the n + 1 # block; S9, obtaining the local coordinate data of the six control points when the n # block is used as the matching block to prefabricate the n + 1 # block through the global-local coordinate conversion, which has the beneficial effect that the real beam block axis deviation angle can be obtained, and the calculation accuracy of the corrected coordinate of the prefabricated beam block is improved.