In this study, a low-complexity dual-polarization carrier phase recovery algorithm has been proposed based on a simplified extended Kalman filter (EKF),which is called XY-EKF algorithm. The signal component required by the Kalman filter is reduced by estimating and compensating for the phase offset between two polarizations. Further, the phase recovery of two polarizations is performed only using the real part (imaginary part) of the X polarization state and the imaginary part (real part) of the Y polarization state, thereby reducing the complexity of the algorithm while maintaining the estimation accuracy. The XY-EKF algorithm is applied to the dual-polarization 16QAM coherent optical transmission system with transmission rate of 224 Gbit/s. The simulation results denote that XY-EKF algorithm exhibits a performance similar to that exhibited by classical EKF algorithm when the products of the laser linewidth and symbol duration are 10 ^-5 and 10 ^-4 with a 1/3 reduction in complexity. Furthermore, when the BER is 3.8×10 ^-3, the linewidth tolerance of the XY-EKF algorithm is 1 MHz higher than that of the EKF algorithm with an identical optical signal-to-noise ratio.