Abstract: An all-sliming cyanidation CIP gold leaching plant in Yunnan Province carried out technical renovation on the bottleneck factors detrimental to production capacity improvement and cost control based on flow sheet investigation in order to improve production capacity and lower cost per ton ore.By optimizing the thickness of fixed jaw of crushers,grid holes on the grid plate of semi-auto mills and the height of hoisting springs in the shell liner,the production capacity is improved from 4 037.75 t/d to 4 231.05 t/d,and the ore-dressing cost is lowered from 100.77 yuan/t to 96.69 yuan/t,while the gold and silver recovery index is not affected.The renovation effect is good and the economic profits are evident.