The invention relates to a magnetic single-component powdered ink, comprising the following components in weight percent: resin, 30-70 wt%; magnetic powder, 25-60wt%; colorant, 0-10wt%; paraffin, 2-10 wt%; charged agent, 0.1-4wt%; alkaline earth metal oxide, 0.1-10wt%; and additive 0.1-5wt%; and its preparing process: weighing resin, magnetic powder, paraffin, charged agent and alkaline earth metal oxide in proportion, putting in a mixer and fully mixing, rolling into sheets by a mixing roll, crushing and classifying and obtaining the classified products, adding in the additive, and finally mixing by mixer and screening to make it. And it has advantages of stabilizing image quality, strengthening blackening, improving blackening uniformity and persistence, reducing bottom ash and distinct gradation, as well as strong universality, low cost, easy to control and less pollution.