The invention discloses a thin-substrate phase 
amplitude correction quari-yagi difference beam planar 
horn antenna, and relates to a 
horn antenna. The thin-substrate phase 
amplitude correction quari-yagi difference beam planar 
horn antenna comprises a micro-strip feeder (2), a horn antenna body (3) and quari-yagi antennas (4), wherein the micro-strip feeder (2), the horn antenna body (3) and the quari-yagi antennas (4) are arranged on a 
dielectric substrate (1), the horn antenna body (3) comprises a first 
metal plane (7), a second 
metal plane (8) and two metallization through hole horn side walls (9), the horn antenna body (3) is provided with metallization through an odd number of hole arrays (11), and an even number of 
dielectric-loaded waveguides (15), on an aperture surface (10) of the horn antenna body (3), the widths of the 
dielectric-loaded waveguides (15) are equal, the dielectric-loaded waveguides (15) are connected with the quari-yagi antennas (4) which comprise active oscillators (21) and passive oscillators (22), and a left-half antenna (13) and a right-half antenna (14) are arranged symmetrically. Electromagnetic 
waves can reach the quari-yagi antennas in an equal-amplitude and in-phase mode and then carry out 
radiation, and the direction of polarization of a 
radiation field is parallel to the 
dielectric substrate; according to the thin-substrate phase 
amplitude correction quari-yagi difference beam planar horn antenna, the thin substrate can be adopted, and the thin-substrate phase amplitude correction quari-yagi difference beam planar horn antenna is high in 
gain, large in zero drawdown, low in cost and compact in structure.