In the traditional system of photovoltaic inverter are generally used the bridge type circuit. Directed towards bridge circuit for the direct problems，the continued flow diode brought about by the poor performance of the power loss，this paper presents a new inverter circuits with BUCK by dual structure，and sets a frequency hysteresis current control methods to control the power switch on-off. Through MATLAB/SIMULINK of single-phase and three-phase grid-connected simulation and test it，double-BUCK inverter circuits can achieve high switching frequency and system efficiency，steady-state and transient performance of traditional bridge inverter circuits are obvious improved，so that the entire photovoltaic inverter system more potential applications.