We have proposed a magneto-optical photonic crystal (MOPC) waveguide that can not only realize highly directional radiation but also work as an electromagnetic (EM) wave receiver. This waveguide consists of a square MOPC and a covering layer of Al2O3 PC tilted at 45° that allows for the penetration of EM waves. Due to the broken time-reversal symmetry caused by an external magnetic field, there exists a unidirectional leaky topological edge state within the photonic bandgap. Such the leaky edge state transmits unidirectionally and radiates into the air simultaneously, leading to a broadside radiation beam with a low half-power beam width of less than 4°. More importantly, the radiation direction of the beam can be tuned over a wide angular range by adjusting the operation frequency or the magnetic field strength. Besides, this designed waveguide can also act as a tunable receiver for capturing incident EM waves effectively. These results have potential for various practical applications, such as antennas and sensors.