The application of Direction of arrival (DOA) estimation with antenna arrays in the scanning radar system can enhance the precision and differentiated ability, and is of some value. The unified frame of high-resolution parameter estimation algorithm for scanned radar is proposed based on the research on them. Various typical algorithms, such as MUSIC, MDMUSIC, ML, and WSF, can be consistent with the unified frame. The unified frame is the universal theoretical basis of high-resolution parameter estimation algorithm for scanned radar. Then, the Cramer-Rao Bound (CRB) of these algorithms is deduced. Finally, the performances of these algorithms are compared through simulation experiments.