The　typical　biomass　fuels　(made　of　corn　cob,　corn　stalks,　soybean　stalks,　straw　stalks,　pine,　chestnut　branches,　peach　branches)　and　civil　coal　(bituminous　coal,　honeycomb　coal)　were　selected　in　Beijing　to　carry　out　simulated　combustion　experiments　in　the　laboratory.　The　whole-process　online　monitoring　of　NOx,　SO2　and　CO　in　flue　gas　was　carried　out　using　Thermo　Fisher　42i　chemiluminescence　NO-NO2-NOx　analyzer,　43i　pulsed　fluorescence　SO2　analyzer　and　48i　CO　analyzer.　The　particle　samples　were　collected　and　the　water-soluble　inorganic　ions　in　the　particles　of　different　particle　sizes　were　measured　by　ICS　90A　and　ICS2000ion　chromatograph.　The　results　showed　that　the　average　emission　factors　of　SO2　from　three　kinds　of　civil　fuels　were　civil　coal　＞fuelwood＞　straw;　CO　emission　factors　were　straw　＞　civil　coal　＞fuelwood;　and　NOx　emission　factors　were　fuelwood＞　Civil　coal　＞　straw.The　content　of　SO42-　in　PM2.5　of　firewood　combustion　is　the　highest,　accounting　for　22%~30%　of　the　total　water-soluble　ions.　K+　takes　an　absolute　advantage　in　the　composition　of　water-soluble　ions　in　PM2.5　of　straw,　accounting　for　36%~49%　of　the　total　water-soluble　ions.　Among　the　three　types　of　civil　fuels,　straw　combustion　has　the　highest　emission　factor　of　water-soluble　inorganic　ions,　followed　by　fuelwood　fuel　and　civil　coal.　Nine　kinds　of　water-soluble　inorganic　ions　(Na+,　K+,　Mg2+,　Ca2+,　NH4+,　F-,　Cl-,　NO3-,　SO42-)　were　analyzed　in　this　experiment.　The　emission　factors　of　Na+,　K+,　NH4+,　F-　from　firewood　combustion　are　the　largest　in　the　the　range　of　0~2.5μm,　while　those　of　Mg2+　and　Ca2+　are　the　largest　in　the　in　the　range　of　2.5~10μm.　Except　Ca2+,　Mg　2+,　the　emission　factors　of　other　ions　from　straw　fuels　reached　the　maximum　in　the　range　of　0~2.5μm　particle　size.　For　bituminous　coal,　except　K+,　Mg2+　and　Ca2+,　the　emission　factors　of　other　ions　reach　the　maximum　in　the　particle　size　range　of　0~2.5μm.　The　emission　factors　of　Na+,　K+,　Cl-,　NO3-,　SO42-　in　honeycomb　coal　reach　the　maximum　in　the　range　of　0~2.5μm　particle　size.　©　2019,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.