Based on the strong nonlinear characteristics of terahertz schottky diode, a compact 220 GHz transceiver front-end for continuous wave frequency modulation radar detection was developed by using multiple harmonic frequency doubling and mixing method. In order to realize the transmitter with high power output, the power amplifier driver of 220 GHz frequency multiplier adopted 4-way power synthesis method to realize 70 GHz 300 mW high-power power amplifier module, and 70 GHz high suppression 7th order cavity bandpass filter to suppress high-order harmonic signal. In order to achieve a high sensitivity receiver, the 220 GHz harmonic mixer adopted hammer-head suppression structure and diode precise noise model to design the circuit structure, and the IF link adopted switch control to achieve dynamic gain control with dynamic range greater than 60 dB. The 220 GHz transceiver front-end achieves a maximum power output of more than 10 mW in the range of 215~225 GHz. The minimum noise figure of the receiver is less than 7 dB, and the gain dynamic range is greater than 60 dB (-7~54 dB).