The invention discloses magnetic particles with various shapes, a preparation method of the magnetic particles and an application of the magnetic particles. The preparation method of the magnetic particles includes the step: heating a system comprising iron salt, templates, shape maintenance agents and solvents and performing reaction to obtain the magnetic particles. The shape maintenance agentsinclude sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, urea or oleylamine; the templates include polyethylene glycol, cetyltriethylammonium bromide, cetyl trimethyl ammoniumbromide, lauryl sodium sulfate or sodium dodecyl benzene sulfonate. Compared with other synthesis methods such as a hydrothermal method, a solvothermal method, a thermal decomposition method and a sol-gel method of the magnetic particles with special shapes, the preparation method has the advantages that the magnetic particles with different shapes can be synthesized by adjusting reaction temperature and reaction time in a raw material system, product particle sizes are at micron level, the preparation method and the steps are simple, raw materials are easy to obtain and low in cost, reactiontemperature is low, reaction in a high-pressure environment is omitted, and the preparation method is suitable for industrial large-scale production.