The utility model provides a fiber connecting device, includes fiber connection piece, optic fibre fastener and cable fixing device, the fiber connection piece includes first bottom plate and first apron, the top of first bottom plate sets up first draw -in groove, the bottom of first apron sets up first fixture block, a first fixture block and a card slot well -matched, first bottom plate top sets up first recess, the cross section of first recess is narrow structure under the width, first apron bottom sets up first lug, first lug forms the first through -hole that supplies naked fibre to pass through with first recess, first lug and the fixed naked fibre of first recess, the fiber connection piece cup joints in the inside of optic fibre fastener, cable fixing device is connected at the both ends of optic fibre fastener. The utility model has the advantages of make the fiber connection more stable, be difficult to drop, and it is higher to dock precision.