A D-band（110~170 GHz） direct detection radiometer front-end which consists of detector module， low noise amplifier module and standard gain horn antenna. The D-band detector is designed and fabricated based on zero-bias Schottky barrier diode HSCH-9161 and the measurement shows that the voltage sensitivity is larger than 400 mV/mW between 110~140 GHz， larger than 120 mV/mW in D-band and the maximal value reaches about 1 600 mV/mW@110 GHz. The D-band LNA module is packaged with self-designed MMIC and the module measurement shows the peak gain is 10.8 dB@139 GHz， the gain higher than 7.8 dB from 137 GHz to 144 GHz， the measured input return loss （S11） and output return loss （S22） are better than -5 dB and 8.5 dB in operating frequencies， respectively. Finally， the imaging experiments based on this front-end are carried out.