In this paper,simulation and experimental studies of typical wear fault of the reciprocating machinery connecting rod big end bearing,explore the influence of the wear and tear on the lubrication parameters of the connecting rod big end bearing. Based on the Reynolds equation,by simulating different bearing wear situations: different widths,different depths and different positions, a comprehensive analysis of the associations between the degrees of wear of bearing and lubrication parameters,in particular the bearing temperatures. By installing the temperature sensor in the test unit connecting rod bearings,connecting rod temperature is on-line monitored,and the variation rules of temperature of the bearing under the state of wear are experimental confirmed.