Dynamic Nuclear Polarization (DNP) which is often employed for polarized solid targets, needs free electron doping to transfer high electron polarization to target nuclei. A newly proposed “mechanical-doping” method was applied in preparation of a polarized target material. A solid material having been crushed into small particles with a diameter of about 20 nm, is mixed with a free radical. This allows target nuclei to have more chance to interact with the free electrons or polarized nuclei surrounding the small particles. A first DNP test at a magnetic field of 2.5 T and a temperature of 0.9 K was performed with a sample of LaF_{3} processed in the mechanical-doping method to introduce a free radical TEMPO dispersed in ethanol. ^{19}F polarizations of 3.3 % and -2.7 % were achieved. The obtained polarization enhancement for ^{19}F demonstrated effectiveness of the new method.