Terahertz focal plane imaging is a practical imaging technology with characteristics of rapid imaging and simple structure, which exhibits advantages for terahertz imaging of biological tissue. In this paper, a reflective continuous-wave terahertz focal plane imaging system is built to image fresh pork tissue, rat brain tissue, and human glioma tissue. It is found that the scattering of targets’ uneven surface can be reduced by adding imaging window. Meanwhile, non-uniform illumination can be eliminated by flat field correction. The results show that reflective continuous-wave terahertz focal plane imaging system can be used for the real-time imaging of biological tissue, which provides an effective technical method for the rapid label-free imaging of biological tissue.