Given the shortcomings of existing methods of preparing functionally gradient materials based on PDMS, such as insufficient raw material mixing, a single preparation method, and high preparation cost, a device that incorporates the production and preparation of functionally gradient products is proposed. Simulations using the COMSOL software were employed to determine an optimization model for the mixing conditions during the preparation of functionally gradient material mixtures. Furthermore, the mixing capabilities of the device were compared when using constant-size and variable-size stirrers. The simulation research results indicate that the preparation device, in combination with the variable-size stirrer, can effectively stir the mixing. The mixing efficiency of the device when using the variable-size stirrer increased by approximately 36 % from that when using the constant-size stirrer. Actual samples were prepared and observed using a Hitachi electron microscope at a 200x magnification. The observation results show that the SiC particles in the sample prepared with a variable-size stirrer were distributed more uniformly than those in the sample prepared with a constant-size stirrer. The product prepared using the proposed device met the conditions for manufacturing functionally gradient products. [ABSTRACT FROM AUTHOR]