The invention provides an S4R-type circuit applied to a spacecraft and a control method. The S4R-type circuit comprises a main circuit, a shunt circuit and a charging circuit, wherein the main circuitis connected to the input of a solar array and is connected to a bus through two diodes connected in series. The shunt circuit and the charging circuit are respectively connected to the main circuit;the shunt circuit is connected to the main circuit through a shunt MOS transistor; the charging circuit is connected to the main circuit at the middle of the two diodes connected in series. The aboveconnection method can enable the voltage drop of the charging MOS transistor to counteract the voltage drop of one diode. The method comprises the following steps: sampling and judging a bus voltageand a storage battery voltage, and determining the working states of a shunt MOS transistor of the shunt circuit and the charging MOS transistor of the charging circuit. According to the invention, the storage battery can be prevented from raising the bus voltage.