The invention discloses a method used for recycling 
sulfur and 
nitrogen resources from 
flue gas and producing 
hydroxylamine sulphate. The method comprises following steps: 1, boiler 
fuel gas is subjected to pre-dedusting and then 
spray cooling dedusting, after 
spray cooling dedusting, the 
flue gas is mixed with an 
oxidizing agent for oxidation, after oxidation, the 
flue gas is delivered into an absorbing 
tower for circulating spray and synchronous desulphurization and denitration, so that 
flue gas purifying is realized, and an absorption liquid containing SO4<2-> and NO2<-> is obtained; 2, the absorption liquid is discharged, and is used for 
spray cooling dedusting of 
flue gas, wherein NO2<-> in the absorption liquid is reacted with SO2 in 
flue gas, and a 
sulfur nitrogen compound absorption waste liquid is obtained; and 3, the 
sulfur nitrogen compound absorption waste liquid is subjected to defouling and purifying so as to obtain a 
hydroxylamine disulfonate solution, and the 
hydroxylamine disulfonate solution is subjected to 
hydrolysis at 95 to 110 DEG C so as to obtain a 
hydroxylamine sulphate solution, and separation and purification are carried out so as to obtain 
hydroxylamine sulphate solid. The method is capable of solving 
nitrite waste water problems in wet synchronous desulphurization and denitration, realizing recycling of sulfur and nitrogen resources in flue gas, and producing 
hydroxylamine sulphate which is relatively high in economical value.