The volatile characteristics of SMC normal temperature modifier were determined, and the modification mechanism was preliminarily explained by Fourier transform infrared spectroscopy. Furthermore, with different SMC content(0%12%), the mixture mixing and compaction temperature, volume index, stability, residual stability, freeze thaw splitting strength ratio, low temperature bending failure strain were tested. Quantitative determination of CO2,CO,SO2,NOx,PM25,PM10 and benzo(a) pyrene(BaP) produced during the process of mixing in laboratory was carried out. The results show that:(1) the SMC normal temperature modifier belongs to the amide bond containing surfactant, and the modified asphalt formed after mixing asphalt with SMC has strong volatility. The production and construction should be completed within 4hours after the addition of SMC normal temperature modifier and 100hours maintenance time should be guaranteed.(2) SMC can optimize low temperature crack resistance in the range of 0%8% of SMC, but it has deterioration effect on strength, high temperature rutting performance and water stability.(3) To ensure the quality requirements for road use, for SMC 13gradation and SMC 20gradation, the suitable use level of SMC is 6%10% and 6%8% respectively. Under this use level the corresponding mixing temperature range can be reduced to 85105℃, and the compaction temperature range is reduced to 7595℃. Although there is still a certain gap from the normal temperature mixing and paving, the emission of CO2,CO,SO2,NOx and benzo(a)pyrene generated during the mixing process is effectively suppressed, and the emission reduction exceeds 40%.