While researching the thermoelectric effect of the nanocontact, we find that the thermoelectric voltage between both ends of the "Γ"-shaped Ni wire changes significantly by applying an external magnetic field, which we attribute to the influence of magnetic anisotropy of Ni wire. The effect of the external magnetic field always produces an extra force whose direction goes against the temperature gradient. And the extra force clearly corresponds to the magnetic field and temperature difference between both ends of the Ni wire. These results suggest that during studying spin-dependent devices, the testing methods and the configuration of magnetic material need to be noticed seriously in order to avoid interfusing additional electromagnetic signals which may bring about a miscarriage of justice to the experimental results.