The isolated AC-DC matrix converter is a bidirectional converter featuring galvanic isolation and the potential of high-power density. However, to ensure safe operation, the commutation between two bidirectional switches relies on the relative magnitude of input voltages. However, sensor errors and sampling noises can lead to the wrong selection of the commutation sequence, leading to commutation failure. To solve this problem, this paper proposes an SVM strategy to ensure the commutation will happen between two phases with significant differences in magnitude. Moreover, the zero vector is also optimized to reduce narrow pulses, ensuring the gating signals are long enough to finish the commutation procedures. Experimental results are provided to verify the performance of the proposed SVM strategy.