This　paper　proposes　a　deferred　defect-correction　method　for　the　time-dependent　nonlinear　Darcy-Brinkman　model　based　on　the　mixed　finite　element　method.　The　presented　method　combines　the　deferred　correction　strategy　with　the　defect-correction　method　and　involves　two　steps.　In　the　first　step,　a　defect　Darcy-Brinkman　model　is　solved.　Then　in　the　second　step,　a　correction　Darcy-Brinkman　model　based　on　the　deferred　correction　approach　is　solved.　Moreover,　unconditional　stability　and　convergence　of　the　presented　method　are　deduced.　Finally,　several　numerical　examples　are　given　to　support　the　theoretical　analysis.