This paper analyzes the gray projection motion vector estimation algorithm to illustrate the application environment and the characteristics of this algorithm, Indicate the needed of resources when implemented in hardware circuitry. Point at the Characteristics of the algorithm we made the corresponding optimized to make it more suitable for the hardware calculation. We design the corresponding circuit module in the FPGA, this circuit can be achieved only use fewer FPGA logic resources, and does not require any embedded and external processor, DSP or other devices, and the estimated motion vector was very accurate while reducing hardware costs. The final results were verified by simulation and the actual project.