Abstract: An adaptive variable-length linear fitting method is proposed to solve the synchronization problem of the single array output azimuths at different times and the mismatch problem between the fixed length and order fitting function and the arbitrary azimuth curve in the fitting process. In this method, piecewise linear fitting is used to fit the tangent of azimuth trajectory for the first time. Through real-time monitoring of the jump points and by the fitting effect obtained after smoothing (i.e. the proportion of track points before smoothing continuously on the same side of the fitting line segment to the total track points before smoothing), the length of the fitting line segment is changed in real time. The experimental data processing results show that this method can solve the problem of multi-array azimuth synchronization, has good fitting accuracy and fast calculation speed to arbitrary azimuth trajectory curves, and provides support for the subsequent multi-array azimuth trajectory association and fusion processing.