Abstract: To achieve the minimum coal pillar width through "mining-filling-leaving" coordinate mining new technology to control strata movement, the design principles and layout forms were discussed. Using similar material test and numerical simulation, we achieved the relationship between coal pillar failure width and mining height or mining depth. The test showed that backfill next to the coal pillar can reduce the pillar width and enhance the pillar strength. The failure width of coal pillar unilateral backfill is 29.8% to 33.1% less than that of pillar without backfill next to it. So, in order to stabilize coal pillar with unilateral backfill, the pillar width must be greater than (0.006 4 to 0.006 8) MH.