Hazardous　heavy　metals　in　Municipal　Solid　Waste　Incineration　(MSWI)　fly　ash　are　a　threat　to　the　environment　and　ecosystems.　The　objective　of　the　work　is　to　investigate　the　solidification　of　MSWI　fly　ash　and　the　immobilization　of　the　heavy　metals　through　alkaline　activation　reaction　with　waste　glass　as　an　additive.　Compressive　strength　measurement,　X-ray　diffraction　(XRD),　29Si　nuclear　magnetic　resonance　spectroscopy　(29Si　NMR)　and　scanning　electron　microscope　(SEM)　were　performed　to　evaluate　the　solidification　effect　and　characterize　the　microstructure　of　alkali-activated　MSWI　fly　ash-based　mortars.　The　leaching　test,　back-scattered　electron　microscopy　(BSE)　and　X-ray　photoelectron　spectroscopy　(XPS)　were　conducted　to　determine　the　heavy　metals＇　immobilization　effect　and　their　immobilization　forms.　It　was　found　that　waste　glass　addition　effectively　reinforced　the　solidification　of　MSWI　fly　ash　and　immobilized　the　heavy　metals.　With　40%　addition　of　waste　glass,　the　compressive　strength　reached　a　maximum　of　3.55　MPa.　The　immobilization　efficiency　of　Cr　increased　with　the　addition　of　waste　glass,　while　that　of　Cu,　Pb,　Zn　and　Cd　is　dependent　on　the　eluant　final　pH,　which　decreased　with　the　decrease　of　eluant　final　pH.　The　main　immobilization　forms　include　physical　encapsulation,　the　formation　of　alkaline　environment　and　the　generation　of　silicate　compounds.