Abstract: Abstract:The performance parameters, the main structures and the unload process flow of the wagon tipper were introduced. The reasons of three wagon derailment accidents inside the wagon tipper of Huadian Guigang Power Generation Company Limited were analyzed. Some effective measures were adopted，and similar accident was eradicated completely.

Key words: Keywords:wagon tipper, derailment, press wagon to proper position, close up to wagon to proper position, programmable logic controller (PLC)