The invention relates to the technical field of computers, and particularly relates to a USB input-output interface for computer host data transmission. The interior of a shell is connected with a connecting plug in a clamping manner, a sliding rail is fixedly connected into the shell, a baffle is slidably connected into the sliding rail, a support is fixedly connected to the left side of the sliding rail, a pressing plate is rotatably connected to the left side of the support, a limiting hole is formed in the bottom end of the sliding rail, a fixing frame is slidably connected to the top endof the sliding rail, a buffer plate is fixedly connected to the right side of the fixing frame, and a limiting block is slidably connected to the left side of the fixing frame. When the bottom end ofthe pressing plate is pressed to the leftmost side by a bayonet lock, the push force of the push rod to the limiting block is stopped, the limiting block is clamped in the limiting groove, the bufferplate is compressed at the moment, the USB interface is firmly fixed in the shell, and data loss caused by data transmission failure due to poor contact between the plug interface and the USB interface when the USB interface is loosened during data transmission is prevented.