Vibration　modelling　is　a　key　link　to　explore　the　cognitive　rules　in　fault　diagnosis.　In　order　to　foresee　the　vibration　characteristics　accurately,　the　dynamic　contact　among　joint　interfaces　and　vibration　transmission　path　of　ball　bearing　are　well　studied.　A　novel　methodology　for　multi-body　vibration　modelling　of　ball　bearing-rotor　system　with　bearing　inner　race-balls-outer　race-pedestal　is　presented.　Additionally,　the　mathematical　formulation　is　derived　with　consideration　of　the　nonlinear　spring　at　the　contact　point　between　ball　and　raceway.　Then,　the　progressive　processes　of　single　and　compound　multi-defects　are　described　by　using　bearing　practical　kinematics　and　the　vibration　responses　are　systematically　analysed.　Compared　with　the　experimental　results,　the　fault　frequency　and　its　harmonic　components　are　clearly　observed　and　achieved　better　consistency.　Moreover,　for　compound　fault,　an　important　observation　is　that　the　strength　imbalance　and　mutual　restraint　of　the　vibration　amplitude　due　to　the　vectors　superposition　of　different　frequency　components.　Further,　the　Lempel-Ziv　complexity　measure　is　also　employed　to　investigate　the　response　of　signature　variations.　The　results　show　that　the　Lempel-Ziv　complexity　measure　used　as　a　quantitative　criterion　can　effectively　evaluate　the　single　and　compound　fault　of　ball　bearings.