Reynolds equation governed journal bearing subjected to dynamic load is deduced.Oil pressure distribution is obtained by using the finite difference method to solve the equation.The Mises stress field is calculated based on the above pressure distribution using contact mechanical analysis.The results are compared to some classical research conclusions accepted widely to confirm the program.And it shows that the calculation method is reliable.Then the characteristic of oil pressure is investigated when journal bearing is subjected to different waveform shock loading

for example step change waveform

sine waveform and mutation waveform shock.And oil pressure and Mises stress of journal bearing of shipboard gear case subjected to shock loading are calculated.Conclusions show that the three-dimensional distribution of oil pressure is approximated to parabolic and the maximum Mises stress is shifted to endosexine gradually.The stress is increased when closed to endosexine.And the maximum stress is in the domain of maximum hydrodynamic pressure.