The invention discloses a field bus type signal distributor. A bus head fixing device is arranged on a bus outlet and comprises a double-head hollow bolt, a hollow nut, a fixing nut and a bus sleeve, a limiting protrusion is arranged between a first end and a second end of the outer side of the double-head hollow bolt, the first end of the double-head hollow bolt is arranged in the bus outlet through the fixing nut, the bus sleeve is arranged on the inner side of the double-head hollow bolt, an expansion rubber head is arranged at a position, close to the second end of the double-head hollow bolt, of the bus sleeve, the hollow nut is arranged at the second end of the double-head hollow bolt, a conical face is arranged inside the hollow nut and compresses the expansion rubber head when the hollow nut is tightly screwed on the double-head hollow bolt, and a bus outlet marking word is arranged at a position, above the bus outlet, on a terminal box. The bus head fixing device is arranged on the bus outlet, so that a bus head can be fixed tightly; a wrench is arranged on the other side face of a cuboid, so that the problem of demounting and mounting for temporary maintenance and inspection can be solved.