The invention discloses an energy-saving and emission-reducing terahertz activating combustion-supporting oil inlet pipe. The oil inlet pipe comprises an oil inlet pipe body, wherein the oil inlet pipe body communicates with a fuel oil muffler, is sleeved with an activating combustion-supporting device and is connected with a plurality of positioning and mounting buckles in a clamped mode, a resonance plate is arranged in the fuel oil muffler, the positioning and mounting buckles are composed of buckling plates, first adjusting plates, second adjusting plates and connecting panels, and the activating combustion-supporting device can be used for dispersing terahertz waves. The oil inlet pipe is simple in structure and reasonable in design, the built-in fuel oil muffler is arranged, so thatfuel oil noise can be greatly reduced, the positioning and mounting buckles are used for positioning and mounting, simplicity, speediness and convenience are achieved, oil pipe deformation and flow section reduction cannot be caused, the normal supply of a fuel oil is guaranteed, meanwhile, the activation effect of the terahertz waves is combined, the activating combustion-supporting device is arranged, so that fuel oil molecules can be activated, the combustion efficiency of the fuel oil is improved, the effects of saving energy, improving power and reducing emission are achieved, a terahertzmetamaterial is simple in preparation method, and is low in cost, the divergent terahertz waves of the terahertz metamaterial is high in divergence rate, good in penetration property, and long in dispersion time.