This paper presents a novel 4-level converter with switch capacitor and boost circuit, meanwhile, introduces its control strategy for a three-phase switched reluctance (SR) drive. The proposed 4-level converter adds one switch, two diodes, one capacitor and one inductance to the front end of a conventional asymmetric converter. The added capacitor and original dc-link capacitor could be connected both in series and in parallel. The performance of SRM is closely related to the supply voltage. High voltage can reduce the time that current flows within the commutation period, and improve the output torque. However, high voltage is not always favorable. For example, higher voltage in the range of low rotational speeds will improve transistors switching frequency, and that causes rise of switching losses. Therefore, the converter having variable output voltage is very useful. The terminal voltage of the converter side is at general dc-link capacitor voltage. Meanwhile, the voltage also could be up to a double dc-link capacitor voltage level to adapt different operation conditions. In this paper, a detailed analysis of current-overlap modes is also presented. The compared simulation and experiments are done. The results verify the performance of the proposed converter.