To solve the problem that the rotor estimation accuracy is greatly affected by parameter nonlinearity and high frequency oscillation, when the synchronous reluctance motor adopts the sensorless control system.This article proposes a new flux saturation model considering cross saturation effect applied to sensorless control of SynRM. The magnetic flux saturation data obtained by the hysteresis voltage injection method is used to estimate the model parameters, and the motor model under accurate magnetic flux saturation is obtained. The proposed magnetic flux saturation model is applied to the position sensorless control system of the synchronous reluctance motor. The proposed magnetic flux saturation model can effectively represent cross saturation and satisfy the reciprocity condition, and solve the nonlinear relationship between SynRM current and flux linkage. Finally, builting an experimental platform to verify the validity and correctness of the theoretical and experimental analysis.