To develop a high precision Micro Coordinate Measuring Machine (Micro-CMM), it is important to evaluate an X-Y stage on the Micro-CMM. A precision multi-probe measurement system has been designed and developed for simultaneously measuring the yaw and straightness errors of the X-Y stage. In the system, an autocollimator measures the yaw error of the stage, and two laser interferometers measure the profile of a standard mirror which is fixed on the X-Y stage. The straightness error is reconstructed by the application of simultaneous equation and least-squares methods, and the uncertainty associated with the multi-probe method is simulated. When the interval of the laser interferometers equals 10 mm, the standard deviation of multi-probe method using the high accuracy autocollimator and the laser interferometers is about 10 nm. The simulation results satisfy our purpose for the uncertainty of 50 nm, and practical considerations are discussed.