Solid-state doubler is the crucial component in terahertz source application. How to make use of nonlinear devices to improve the conversion efficiency of terahertz doubler is the key to design terahertz solid-state circuits. Two design methods of solid-state terahertz doubler are introduced and two different topology structures of 170 GHz doubler are designed. The direct matching method and the transmission mode matching are employed respectively in the two different 170 GHz doubler topologies. Based on the two structure models, 3D finite element simulation and nonlinear harmonic balance simulation are carried out. Simulation results indicate that the conversion efficiency of the doubler is above 15% and the output power is up to 7 mW within 160 GHz-180 GHz output frequency when driven by 17 dBm input power. Simple comparison and analysis are made between the two doubler structures designed by two different matching methods, which lays foundation for the future terahertz doubler design and research.