Abstract: The vicinity of the tunnel lining trolley is an important working area for construction workers.During the slag discharge process,the dust concentration in the trolley area remains high,which seriously endangers the life and health of workers.In order to clarify the influence of dust source parameters and slag transportation on the dust concentration of the lining trolley,this paper uses the numerical simulation method and combines the field monitoring results to study the variation law of the dust concentration of the lining trolley under different dust source mass flow rates and dust source respirable dust ratios.The influence of dump truck migration and different dust amount on dust distribution was analyzed.At the same time,the tunnel ventilation and dust removal measures were optimized based on the concept of transverse ventilation.The results show that the peak dust concentration in the lining trolley area is positively correlated with the mass flow rate of dust source and the proportion of respirable dust from dust source.When the mass flow rate is 0.012kg/s,the peak dust concentration reaches 67.8mg/m³.When the proportion of respirable dust was 65%,the peak dust concentration increased to 15.1mg/m³.In the process of slag transportation,the dust concentration of the lining trolley increased rapidly and reached a peak of 177.6mg/m³ in a short time after the vehicle passed,and then gradually decreased and returned to the state before migration.The dust concentration of lining trolley is positively correlated with the amount of dust.When there is no dust,the vehicle migration process can accelerate the dust dissipation in the lining trolley area,and the dust concentration after migration is only 13.1mg/m³.When the dust amount is 0.0121kg/s,the vehicle dust will lead to an increase in the dust concentration in the lining trolley area,and the dust concentration reaches 51.4mg/m³ after migration.The ventilation optimization scheme based on the concept of transverse ventilation can effectively improve the slag discharge environment in the lining trolley area.