Mud-cracking　of　the　sintered　silver　(Ag)　layer　of　the　SiC　power　module　is　commonly　found　during　power　cycling　tests.　In　this　article,　the　effect　of　the　mud-cracking　of　sintered　Ag　on　the　heat　transfer　behaviors　of　SiC　power　module　is　studied　based　on　a　Voronoi　tessellation　model.　This　model　is　verified　to　be　reasonable　on　the　prediction　of　the　equivalent　thermal　conductivity　of　sintered　Ag　as　well　as　the　thermal　resistance　of　power　module.　The　effect　of　the　crack　ratio　on　the　equivalent　thermal　conductivity　of　sintered　Ag　is　studied　and　an　empirical　model　is　proposed　to　predict　the　equivalent　thermal　conductivity　of　sintered　Ag　containing　different　mud-cracking　ratios.　The　effect　of　mud-cracking　ratio,　chip　size,　sintered　Ag　thickness,　and　porosity　on　the　thermal　resistance　of　power　module　are　studied.　An　equivalent　model　to　study　the　heat　transfer　behaviors　of　the　power　module　with　mud-cracking　is　also　developed　to　improve　the　calculation　efficiency.　This　article　establishes　a　new　method　to　quantitively　study　the　heat　transfer　behaviors　of　the　power　module　under　power　cycling　condition.