With　the　rapid　development　of　science　and　technology,　regional　economy　collectivization　and　global　economic　integration,　more　and　more　enterprises　adopt　to　establish　strategic　alliances,　and　then　instability　and　disintegration　have　become　a　conspicuous　problem.　Taking　Cournot　oligopolistic　competition　as　an　example,　this　paper　has　analyzed　the　mechanism　of　strategic　alliances　stability　based　on　repeated　game　theory,　and　drew　an　conclusion　that　the　essence　of　strategic　alliances　is　stable.