In order to improve the measurement efficiency of theodolite based on visual guidance, a method for measuring the target point in the space precisely is proposed. Applying electronic laser theodolite to do the single-axis scanning, we can obtain the parallel grid model of planar scanning trace. This model efficiently helps us establish a relationship between the scanning length and the rotating angle of the single-axis. Under the consideration of the remarkable effect that the lens distortion may be caused on the measurement results, we employ an interpolation algorithm in order to realize a more accurate measured value. The result shows that, after the distortion reclamation, the accuracy within thevolume of 10 m×10 m can achieve 3″, which not only improves the measurement efficiency but guarantees the accuracy as well.