The invention provides a detecting mistake-proof system applicable to an electronic part production line and a method of the detecting mistake-proof system. The detecting mistake-proof system comprises a main control unit, a data center, a bar code unit, an assembling unit and a detecting unit. The assembling unit comprises an automatic welding machine. Under the overall control of the main control unit and through the matching of the data center, the bar code unit, the assembling unit and the detecting unit, detecting control and fault prevention of the assembly line are conducted. Problems which occur in an assembly line production process can be found out timely, through the monitoring method where various means suck as element scanning are combined, mistakes can be reported effectively, timely processing of the production mistakes is benefited, the number of broken machines is reduced, cost consumption is avoided, production personnel are reduced, scrapped products are reduced, cost for maintaining damaged products is reduced, manpower and task time consumed by reworking are reduced, normal production task time which is lost is reduced, at the same time, reducing of the whole production cost is benefited, efficiency of a production workshop is improved and product quality is improved.