A single method for simultaneously measuring 2-D rotational angles is proposed by using a collimation laser. Compared with the traditional autocollimator measurement method, the proposed method can also be applied to longer distance and higher precision angular measurement. The 2-D angular drift of the reference datum beam is suppressed by a factor of 10 via expansion. A traditional single lens in front of the detector is replaced by combination lenses to increase the sensitivity and compactibility. The measurement principle of the 2-D angles is also analyzed. The feasibility and stability of the presented system are verified by comparison with the Renishaw ML10 laser interference measuring system. The experimental results show that the linear correlativity is 0.99999 and the point-to-point standard deviation error is less than ±0.2 arcsec in a ±60-arcsec range and 2000-mm distance. This proposal is most advantageous for simultaneous long distance and high accuracy of 2-D angular errors measurement of a linear guide manner.