A spindle connector including a holder base having two rectangular mounting holes arranged at two opposite ends at right angles, two annular grooves spaced around the periphery, and two radial pin holes respectively made through the annular grooves for mounting a respective pin to hold a respective transmission shaft to the holder base; a transmission shaft having two opposite flat coupling portions at two opposite ends for fitting into one rectangular mounting hole on the holder base and two pin holes respectively arranged at the coupling portions at right angles for connection to one pin hole on the molder base; two binding rings respectively mounted around the annular grooves to hold a respective pin in each pin hole on the holder base; and a socket sleeved onto one end of the holder base and covered over the linked coupling portion of the transmission shaft for protection.