InP-based HEMT samples were prepared by molecular beam epitaxy(MBE). The sample mobility at room temperature reached 10 289 cm2/(V·s). The terahertz detector coupled with a bow-tie antenna was fabricated by photolithography, etching, magnetron sputtering, spot welding. The bow-tie antenna used in the device was optimized by simulation with HFSS, so that the optimized antenna parameter of S11 was -40 dB, the voltage standing wave ratio(VSWR) was 1.15, gain was 6 dB and impedance matching with the two-dimensional electronic gas(2DEG) channel. The device was measured by VDI′s 0.3 THz Schottky diode terahertz source. The measurement results show that the device noise equivalent power (NEP) is 4 nW/Hz1/2 at room temperature, and the detection response rate is 46 V/W, the device response time is better than 330 μs.