The　rolling　ball　bearing　with　double　half-inner　rings　is　widely　used　in　rotating　machinery　due　to　its　remarkable　space-saving　structure,　convenience　of　installation　and　load-carrying　capacity.　This　paper　focuses　on　dynamic　modeling　and　abnormal　contact　analysis　of　rolling　ball　bearing　with　double　half-inner　rings.　Firstly,　an　analytic　dynamic　model　of　the　bearing　is　proposed　with　consideration　of　lubricant　resistance　and　cage　effect　under　working　conditions.　Then,　the　dynamic　model　is　applied　for　the　contact　analysis　between　rolling　balls　and　bearing　rings,　and　the　boundary　between　normal　contact　(i.e.,　two-point　contact)　and　abnormal　contact　(i.e.,　three-point　contact)　is　given.　All　the　numerical　simulations　are　verified　with　the　experiments.　The　results　can　provide　helpful　guidance　for　the　design　and　troubleshoot　of　rolling　ball　bearings　with　double　half-inner　rings.　©　2020　Elsevier　Ltd