The utility model discloses a lightweight long -life hub unit assembly, its characteristics are to comprise wheel hub (1), outer bearing (2), inner bearing (3), bearing spacer ring (4), inner oil seal (5), dustproof oil seal (6), O type circle (7), outer oil blanket (8), lock nut (9) and wheel bolt (10) to wholly assemble on spindle nose (11), realize rotating through the moment of torsion that the transaxle semi -axis provided, inside and outside diaxon holds the solely lubricated realization in chamber separately, has improved lubricating quality, has increased life, has still solved the lubricated extravagant problem of grease of the full hub of ordinary wheel hub, has reduced assembly and use cost, the diaxon holds has increased oil blanket seat circle function, has simplified the structure, has reduced part quantity, can shorten the whole length of wheel hub assembly by a wide margin, realizes the design lightweight, dustproof oil seal still increased the inner bearing and has kept off by spacing in the dirt -proof while, had the effect of changeing the preface frock concurrently, had reduced the design cost.