In view of the particularity and importance of pellets，a geometrical scale and density measuring system for nuclear fuel pellets is designed. The system realizes bi-dimensional，synchronous and high-precision measurement for pellets’ height and diameter by using optical noncontact way，and uses multi-point scanning for diameter due to the particular require of diameter measurement. Measuring pellets’ weight while finishing the measurement of geometrical scale，the system achieves high-precision and high-speed measurement for pellets’ geometrical scale and density. It can measure the pellets with diameter over 1 μm and height over 3 μm. Its measuring speed is 7 pellets/min and the function such as data displaying in real time，alarm，storage and inquiry，automatic report generation and user management are endowed.