To　overcome　the　issue　of　substandard　nitrogen　and　phosphorus　discharge,　resulting　from　the　low　carbon/ni-trogen　(C/N)　ratio　of　municipal　wastewater,　immobilized　filler　was　used　to　re-hydrolyze　the　alkaline　fermen-tation　liquid　of　waste　activate　sludge　(WAS)　as　a　nitrogen　removing　carbon　source.　The　complex　organic　matter　was　further　hydrolyzed　and　its　denitrification　efficiency　as　a　carbon　source　for　nitrogen　removal　was　improved.　Volatile　fatty　acids　increased　from　1605　&　PLUSMN;　5　mg/L　to　2546　+/-　37　mg/L　after　re-hydrolysis　of　mixed-alkali　sludge　fermentation　liquid,　and　complex　organic　matter,　such　as　fulvic　acids,　humic　acids,　class　I　aromatic　proteins,　and　soluble　microbial　products　were　hydrolyzed　into　small-molecule　organics.　When　the　re-hydrolysis　fermentation　liquid　(RH-SFL)　was　used　as　the　carbon　source　for　nitrogen　removal,　the　nitrogen　removal　effect　was　close　to　sodium　acetate　and　the　nitrogen　removal　rate　(NRR)　was　up　to　98.5　+/-　0.5%.　According　to　the　NOX--N　removal　curve,　the　reaction　rate　of　RH-SFL　was　significantly　higher　than　before　re-hydrolysis　(nRH-SFL)　(0.486　＞　0.38).　This　technology　can　significantly　improve　the　effective　organic　quality　in　the　alkaline　fermentation　liquid　of　WAS,　which　can　be　more　easily　utilized　by　denitrifying　bacteria.　This　provides　a　feasible　and　effective　solution　for　nitrogen　removal　in　municipal　wastewater　with　insufficient　carbon.