Cascaded H-bridge rectifier(CHBR)are usually used in the high-voltage situations such as APF(Active Power Filter)and PET(Power Electronic Transformer). Further, the capacitor voltage balancing is an important issue of this topology. Based on the mathematical model of CHBR, a novel PI-based capacitor voltage balancing method is proposed with the carrier phase-shifted SPWM technique. The relationship between the modulation index and the active power of cells is deduced by the mathematical analysis, and the voltage range of proposed capacitor voltage balance control is derived. A three-module CHBR simulation model, as well as an experimental prototype, is built. Experimental results indicate that the presented method has good performance on the capacitor voltage balance.