The paper investigates the micro asperity contact load ratios and lubrication states of the water-lubricated bearing. New coupled models with consideration of micro-scale asperity contact effects are put forward. The relevance of load ratio with transition of lubrication regimes under multi coupled structural parameters and operating conditions are established. The three-dimensional relationships between typical parameters and contact ratio under typical working conditions have been further studied. Characteristic parameters of lubrication regimes transition under multi coupled factors are investigated. The mechanism of regimes transition is revealed at the micro level. Experimental measurements verify the correctness of the revised model. Researches are beneficial for the definition of micro asperity contact load ratio and lubrication regimes transition for such bearings.