The seed-injected terahertz wave parametric production source (is-TPG) is based on stimulated electromagnetic dipole scattering in nonlinear crystals, and has advantages of narrow line width, good coherence, room-temperature operation, and tunability. In this paper, the tuning range, output energy, threshold, and other aspects of continuous/pulsed seed-injected terahertz wave parametric generation source (is/ips-TPG) are investigated based on a 5% molar percentage magnesium oxide doped lithium niobate crystal (MgO∶CLN) of the same composition. Compared to the is-TPG system, the tuning range of the ips-TPG system is expanded by approximately 80%. The 3 dB bandwidths of the is-TPG system and the ips-TPG system are 1 THz and 1.41 THz, respectively, accounting for 51% and 39% of their respective tuning ranges. The ips-TPG system extends the range of the 3dB bandwidth by 41% compared to the is-TPG system. At similar average power densities, ips-TPG produces a stronger THz wave output with a maximum conversion efficiency of 1.01 × 10^-5 due to its higher peak power density lowering the threshold. The injection of different forms of seed light has a significant impact on the terahertz wave parametric radiation sources. The experimental results show that the output characteristics of the ips-TPG system are more prominent and have higher value in practical applications. The paper concludes with an analysis and outlook of its future development.