Abstract: The principle of closed-loop FOG detection of triangular waveform phase compensation and a new detection method are analyzed. For the measurement of rotation velocity on the triangular waveform phase modulation, the expressions of rotation rate and rotated angleθ were deduced. Then the multiperiodic rotation rate measurement was carried out. Through the expansion for the dynamic range, the measurement method was obtained when the rotation rate was at high or extremely low range. The influence of the parameters on the rotation velocity was analyzed. With theory analysis, a new design was implemented by using MCU to realize the signal detection. The design is simple and the cost is low. The flow chart of the circuit is presented. The factors which affect the system measurement precision are also analyzed, and then the solution is given.