The rational simulation method for traffic load of submerged floating tunnel (SFT) and its impact on SFT structure are studied. Firstly, the simulation formula for traffic loads of SFT is carried out by means of referring to simulation method for traffic load of railway and highway and comprehensive considering factors of heel load, road roughness, velocity of vehicles and external incentive loads. And then, the characteristics of traffic loads and the structural vibration displacement response of SFT under different simulation methods are analyzed by means of numerical simulation. The results show that: 1) The calculation results by simulation method proposed coincide with the actual situation of moving vibration load and present characteristics of variability and periodicity. 2) In terms of the structural vibration displacement response, the calculation results of moving concentrated load and moving vibration load are similar and larger than fixed distributed load which is equivalent to static load. The amplitude of moving vibration load is slightly larger than that of moving concentrated load; and it can reflect the effect of dynamic component of traffic load to the structural vibration displacement response; as a result, the moving vibration load is more appropriate to be used as the traffic load of SFT.