During mass production, enterprises face the problem how to deal with quality risk product due to single case. In this article, through two typical connection process in engine production, for example, interference fit and bolt connection, provide an un- conventional analysis methods.Through limited, simple detection and evaluation, can make a relative accuracy judgment for the risk failure product. In fact, whether by means of measurement of sampling audit to handle failure risk rods after pressing in bushings, or for some reason.Risk failure of a uniform set of bolted connections on crankshaft flanges, through targeted analysis, measurement, and fi- nally evaluate the failure risk. Results proved that the analytical methods in this article are both effective, reasonable and economically.