Abstract: Aiming at the problems of 10^# and 11^# close distance coal seams during combined mining in Luzigou Mine of Shanxi Coal Transportation and Marketing Group. Through field investigation, laboratory test, theoretical analysis, mechanical model caculation and numerical simulation combined method, this article studied the failure of coal pillar width, the stability of coal pillar and support pressure distribution and coal pillar support pressure on the floor. By FLAC^3D simulation software, it determined that the reasonable malposition arrangement for the combined mining is 9 m.