Abstract: Large radio telescopes play an important role in various disciplines such as radio astronomy, geodynamics, and deep space exploration. Due to the influence of various factors such as temperature, gravity, and wind load, components including the subreflector, backup structure, and main reflector undergo deformation, thereby compromising antenna efficiency and pointing accuracy. Therefore, it is necessary to measure and adjust the antenna. The real-time correlator is a crucial instrument for antenna measurement. For this purpose, an enhanced real-time correlator based on FPGA (Field Programmable Gate Array) for antenna measurement was designed and implemented. When applied in antenna measurement, compared with the traditional total power measurement method, the enhanced real-time correlator offers advantages such as strong anti-interference capability, high sensitivity, and the ability to perform real-time compensation and interferometric observations of radio sources. It can be applied to various antenna measurement applications, including pointing calibration, subreflector pose adjustment, and main reflector deformation measurement. Scanning radiation pattern test and holographic measurement of the main reflector deformation were conducted on the TM65 m radio telescope using the enhanced real-time correlator. The results verified the accuracy and reliability of this system for antenna measurement.