Method for testing precision of primary observation set of theodolite in horizontal direction

The invention discloses a method for testing precision of a primary observation set of a theodolite in the horizontal direction, which comprises the following steps of: (1) adjusting a multi-tooth indexing table to 0 degree, and arranging the theodolite to be tested on the multi-tooth indexing table; (2) aligning the image of a cross wire captured by a camera to a standard cross wire in a computer, and then returning the angle alpha on the display panel to zero; (3) in a positive lens state, rotating the multi-tooth indexing table by an angle delta beta, then rotating the sighting part to enable the camera to capture an image of the cross wire, and recording a test angle theta 1; (4) executing the step (3) repeatedly, and rotating the multi-tooth indexing table is by the angle delta beta in the same direction every time; (5) switching to a reversing state, and repeating the steps (3)-(4) to obtain a plurality of groups of reversing test angles theta'i, and (6) analyzing thetai and theta'i, and calculating to