Detector samples based on resonant tunneling diode (RTD) are fabricated by molecular beam epitaxy. In order to improve the detection responsivity, the detector uses bowtie antenna to enhance the terahertz electric field intensity, in which the antenna structure is designed with reference to 0.2 THz incident frequency. The terahertz source with an output power of 20 mW is used for testing. Current-voltage (I-V) test is performed with and without THz irradiation at room temperature, and the peak voltage is 1.398 V. The difference between the maximum current values is tested, the detector responsivity is calculated to be of 20 mA·W-1 and the noise equivalent power is 15 nW·Hz-0.5. The response of the detector to the terahertz wave in different directions of incidence is measured, and the enhancement of the antenna on terahertz electric field is verified.