Terahertz interferometric imaging offers considerable potential in many imaging applications due to its simple imaging principle, less detector elements and efficient data acquiring ratio. An interferometric imaging system scheme was proposed based on the research of Terahertz interferometric imaging principle. Simulation experiments were carried out to analyze the impact of imaging frequency, radius of circular array and detector number on imaging quality and frequency bandwidth of the imaging system. The experimental results show that the radius of circular array is smaller while the frequency is higher for available imaging with the other conditions being changeless. Adding detector number would improve the imaging quality but not obvious while bigger than one certain number and the frequency bandwidth of uniform circular array for available imaging is wide. The conclusions from the simulation results may offer some theoretic evidence and technical support for the design of terahertz interferometric imaging system and practical applications.