A 20 L explosion device was used to study the explosion characteristics of fuel-air explosive containing micro/nano-aluminum powder. Results indicated that when adding 5% and 10% nano-aluminum to micro-aluminum， the maximum pressure of mixed powder increased by 24.2% and 58.5%， respectively. The maximum rate of pressure rise increased by 80.6% and 103.4%. The nano-aluminum would not have any contribution to the explosion effect while its content was more than 10%. For the fuel with a solid/liquid ratio of 30/70， while the ignition energy increased from 11.83 J to 28 J， the explosion pressure consequently increased from 0.28 MPa to 0.52 MPa， meanwhile the explosion temperature increased from 834 ℃ to 1118 ℃，indicating that the explosion parameters of FAE could be improved by increasing the ignition energy. Increasing the content of micro/nano aluminum powders could effectively increase the explosion pressure and temperature of FAE.