The invention discloses a passive coherent location radar direction finding system based on an Adcock antenna, mainly solving the problem that angles are precisely measured in an environment with strong direct waves and multi-path interferences. The system mainly comprises a signal branch route signal antenna, a receiver A, a signal processor, a constant false alarm rate (CFAR) and track association module and an angle measurement module. The signal antenna applies the Adcock antenna for receiving moving target echo, direct wave and multi-path. The received signal is filtered and amplified by the receiver A, and is transmitted to the signal processor; an analogue intermediate frequency signal is converted into a digital base-band signal via the signal processor, channel adjustment, clutter canceling and range-Doppler two-dimensional correlation are carried out, and the result is transmitted to the CFAR and track association module; the original track is detected by the CFAR and track association module or a target of a new track is formed by the CFAR and track association module, and the angle of the target is measured by the angle measurement module. The invention can realize precisely measurement of angles in an environment with strong direct waves and multi-path interferences.