The invention relates to a carbon nanotube uniformly and stably loaded with iron-containing nano particles and a preparation method of the carbon nanotube. According to the invention, the carbon nanotube is prepared through the following steps: with a hydroxylated or carboxylation modified multiwalled or single-walled carbon nanotube, a non-ionic polymer surfactant, and an organic iron compound as raw materials and ethyl alcohol or methanol as a medium, reaction is carried out in a high-pressure reaction kettle with the filling amount of 80% for 4-24 h, and the product is heated for 5 minutes to 2 h under the conditions of 250-800 DEG C and inert gas protection. The obtained carbon nanotube uniformly and stably loaded with the iron-containing nano particles is characterized in that the iron-containing nano particles are uniformly loaded on the outer surface of the carbon nanotube, the nano particles are one of ferric oxide, ferroferric oxide, and iron, narrow in particle size distribution, and 5-20 nm in average particle size, and can be stably loaded on the carbon nanotube under the effects of severe mechanical dispersion or ultrasonic dispersion, and the carbon nanotube has a good application prospect in the fields of catalysis, sensors, electromagnetic shielding material, new energy material, biotechnology, high-performance composite material and the like.