In view of the problem that sloping wharf cannot meet the troops global mobile because of poor universality,based on the loading and unloading mode of ro-ro ship with stern straight type springboard T-type berthing at vertical lifting wharf,the water level and time calculation models are established.Based on the two limiting position of stern springboard overlap jointed with the wharf,the water level model deduced out the data range of operation water level.In the time model,tidal fluctuation regularity is regarded as simple harmonic motion.The amendment number of tide height,phase angle,and time interval of tide level and low or high water marks are get in succession,consequently the time table of corresponding tide is get.The correctness of the two models is verified and the data range of water level and time for loading and unloading are get by an example