The invention provides a semimetal magnetic material with high spin polarization. The chemical formula of the material is VxCoyNzMw, wherein N is an III-V group element; M is a transition group element; x is smaller than or equal to 2 and greater than 1; y is smaller than 2 and greater than or equal to 0; z equals to 1; w is smaller than or equal to 1 and greater than or equal to 0; and x+y+z+w equals to 4. A preparation method of the material comprises the following steps of: (1) weighing materials in the proportion of the chemical formula VxCoyNzMw, and putting the materials into an electric arc crucible, wherein N is one or more of Al, Ga, In, Si, Ge, Sn and Sb in the III-V group element, and M is one o more of V, Cr, Mn, Fe and Ni in the transition group element; (2) filling argon in an arc electric furnace after the electric arc furnace is vacuumized, cooling the materials after the materials are subjected to electric arc melting for 2-3min under the protection of a positive pressure of 0.01MPa to 1MPa or flowing argon; and repeating the melting for 3-5 times so that alloy materials are uniformly distributed, and finally obtaining the product. The spin polarization of the semimetal magnetic material is between 90% and 100%, and is between 80% and 96.2% in actual measurement; and therefore, the semimetal magnetic material represents extremely high spin polarization.