Abstract: Aiming at problems like large investment and poor adaptability of overcast stripping system of dragline, a stripping system suitable for thin and medium thickness seam mining has been put forward. The excavator has overcast the overburden in order to expose the coal seam roof, and the hydraulic backhoe standing on the platform for secondary pouring pile has been used to expose the coal seam bench slope, and finally to finish the overcast stripping. Compared with the shovel-truck system, the overcasting technology system can not only avoid the high cost of truck transportation, but also shorten the distance of open-pit stripping. Therefore, even the repeated overcast rate is up to 100%, using the overcast stripping system is still reasonable economically. The case study has shown that, using overcast stripping in Anjialing open-pit coal mine for 11 # coal seam mining can save the cost about 14,000,000 yuan/a.

Key words: overcast stripping, single bucket excavator, narrow cut zone, hydraulic backhoe