The multi-purpose laser welding system (also called as laser mould welder, mould repair) is specially designed for the mould industry and used in repairing of precision moulds, such as mould manufacture for digital products, mobile phone, toy, automobile and motorcycle, and moulding industry. Through the repairing of moulds, it is possible to reuse the moulds, save the production cost and improve the working efficiency significantly. This technology can also be used to modify the design or size of moulds to reduce the development period.