Based on study of space vector modulation, cca novel over-modulation strategy of matrix converter is proposed for the problem of low voltage transfer ratio of matrix converter. According to the relation of the voltage space vector trace and hexagon trace vector, the control level is divided into linear modulation level and over-modulation level. The over modulation strategy is achieved by transforming the voltage modulation coefficient. The simulation results demonstrate that the voltage transfer ratio can be up to 0.955.