Abstract: In a case study of the low-grade gold ores from an overseas mine,an experimental study on the cyanidation of high-pressure roller mill and conventional jaw crusher products is carried out and investigates the effect of the 2 comminution and grinding processes on cyanide leaching of gold.The test results show that through the high-pressure roller mill,the fine grain content in  the ore products is higher than conventional jaw crusher crushing,and the grindability is better than that of the product from conventional crushing.Besides it helps reduce the cost of grinding and improve the column leaching rate of gold.Under the same leaching conditions,the column leaching rate of high-pressure roller mill products is 11-15 percentage points higher than that of the conventional crushing products.The experimental results can be referred to by the gold mine and similar mines when it comes to high-efficient development and comprehensive utilization of resources.