Compact Antenna Test Range(CATR) is an effective alternative method to measure the antenna pattern, however, the existence of the stray signals would significantly degrade the measurement accuracy. The paper proposes an effective method which can effectively eliminate the influence of the stray signals. The proposed method measures the Antenna Under Test(AUT) repeatedly while moving the AUT along any straight line with equidistance. There are different phase factors for each stray signal at different displacements. A Vandermonde matrix can be constructed by using these phase factors. All responses, including the desired response, can be calculated by inverting the Vandermonde matrix. The deviations between the simulations and test data are less than 0.5 dB, which validates the effectiveness of the proposed method.