Pin replacing system, pin replacing method and vehicle production system

The invention relates to a pin replacing system. The system comprises a processor, a vehicle type recognition module, a conveying line, a mechanical arm and a vision guide positioning module, whereinthe vehicle type recognition module, the conveying line, the mechanical arm and the vision guide positioning module carry out signal transmission with the processor, the vehicle type recognition module recognizes an identity type of a vehicle body to be machined, and sends the type to the processor, the processor judges whether an existing pin needs to be replaced or not according to the identitytype of the vehicle body to be machined, if the existing pin needs to be replaced, a pin replacing instruction is sent to the conveying line, the type of a target pin is determined, and the position of the target pin in a pin storehouse is determined. The conveying line conveys a to-be-replaced pin device to a pin replacing station, and sends out an in-position instruction to the processor, afterthe processor receives the