Abstract: The impact of dilution holes with three different areas on the flow rate distribution of a model rectangular trapped vortex combustor was numerically simulated,and the total pressure loss,lean blow-off limit and combustion efficiency of the combustor were experimentally studied under the inlet Mach number was 0.3 and the total temperature was 540K.This shows that,both the flow rate distribution and the performance of the combustor are affected by the dilution holes'areas,and the combustor with larger dilution holes has better combustion performances than the others.