The photoconductive antenna is a very important device in the terahertz region and is widely used in terahertz time-domain spectroscopy technology. This article uses the molecular beam epitaxy method to grow Be-doped InGaAs/InAlAs superlattice as light absorbing materials for 1550 nm laser pumped photoconductive antenna for terahertz detection. The prepared materials have a sheet resistance greater than 10⁶ Ω/sq and an electron mobility of 216 cm²/（V?s）. The active mesa and electrode structure of the detection antenna are prepared using wet etching and magnetron sputtering processes， and the antenna chip is packaged on a PCB board. A detection antenna measurement system is built by employing a domestically produced 1550 nm femtosecond pump laser， and the detection antennas with electrode gaps of 40 μm and 60 μm are characterized. The measurement results indicate that the 60 μm antenna has a wider spectral width and power dynamic range， reaching 4.0 THz and 77.0 dB， respectively.