Compared with the widely used wireless system represented by microwave and wired system represented by optical fiber, terahertz band is expected to break through the bandwidth limit of microwave system in addition to its special spectral characteristics, thereby achieving a large bandwidth comparable to the optical fiber system but possessing the flexibility and intelligence of wireless system. However, it is still a great challenge to achieve broadband, intelligent and long range terahertz systems. The architecture of photonic-electronic converged intelligent terahertz systems is introduced firstly, and then the research progress and further development direction of key technologies such as terahertz source, receiver, channel monitor, array antenna and terahertz photomixer based on photonic-electronic convergence are reviewed and discussed. Here a new approach based on photonic-electronic convergence is discussed in order to solve the bottleneck of a single electronic or photonic approach.