This paper has designed the input and output coupler,Magnetron Injection Gun (MIG) and beam-wave interaction circuit for a W-band gyrotron traveling tube (gyro-TWT) with software simulation. The tube was manufactured according to the optimized results. The gyro-TWT is driven by a voltage of 60 kV and current of 6 A. Hot test predicts its maximum peak output power of 78 kW, 21.7% efficiency at 94 GHz with a gain of 53.9 dB. The bandwidth with peak power greater than 50 kW is about 3.8 GHz. Both the PIC simulation and hot test indicated that the gyro-TWT can work stablely. The periodic lossy dielectric loaded circuit is excellent for suppressing potential spurious oscillations and absolute oscillation.