Abstract: Aiming at the problem that the digital signal is sensitive to the Carrier Frequency Offset (CFO) in the Orthogonal Frequency Division Multiplexing (OFDM) system, a blind carrier frequency offset estimation algorithm (CM-OFDM) based on continuous symbol mean power variance minimization for Constant Modulus-OFDM(CM-OFDM) systems is put forward. The algorithm constructs the cost function in views of the constant modulus of the frequency domain signal, compensates the time domain signal in the CM-OFDM system by testing three frequency offset estimators, and finally estimates the CFO using the Monte Carlo method. In addition, the algorithm uses the forward and inverse transform of Fast Fourier Transform (FFT) to form a unitary matrix, thus the computational complexity of the algorithm will be reduced. Simulation results show that the proposed algorithm can effectively improve the performance of CFO estimation and has good robustness.