Abstract: This paper presents a SOC based digital subdividing system for orthogonal grating Moiré fringes to simplify the complex circuits of traditional electrical subdivision system and to solve the additional error problems. It puts the peripheral circuits into SOC(System on a Chip)and uses software to execute the direction identifying of digital signals, subdividing and real-time counting. The proposed system improves the measurement precise and gives a real time display, having advantages such as simple structure, low cost, and low power consumption.