import arcpy
mxd = arcpy.mapping.MapDocument("current")
for lyr in arcpy.mapping.ListLayers(mxd):
if arcpy.Describe(lyr).dataType==‘FeatureLayer‘:
print lyr.name
lyr.definitionQuery = "DIS=‘GM‘"
原文：https://www.cnblogs.com/yj2010/p/10214507.html