Proposed in this paper is a heat balance-based experiment method for the modeling of SNCR（Selective Non-Catalytic Reduction） injection.The experiments are carried out at a 1∶10 410t/h boiler modeling platform,by which the influences of total flowrate,flow velocity,injector number and injection strategy on the mixing effect are investigated.Moreover,the concept of ideal NOx reduction ratio is introduced to quantify the NOx reduction with different injection strategies.The results indicate that the ideal NOx reduction ratio increases from 47% to 58% with the total flowrate and increases by 8% with the flow velocity,and that it varies from 44% to 52% at different injection strategies.Moreover,it is found that ammonia/NO ratio also has a significantly positive effect on the ideal NOx reduction ratio.