A computer host with bus interface includes a power supply and a motherboard. The power supply has a main power system and a standby power system. The DC power outputted by the standby power system is used to drive a power on/off unit, which is used for outputting a computer operating signal and a computer shutdown signal. The motherboard has a logic operation circuit and a data transmission port electrically connected to inner electronic device. A bus interface is installed on the computer host and the bus interface has a power transmission terminal and a data transmission terminal. The data transmission terminal is electrically connected with the data transmission port of the motherboard, and the power transmission terminal is electrically connected to the standby power system such that the bus interface can receive the DC power from the standby power system when the computer host is under operation or shutdown.