Background　Mandibular　defects　can　greatly　affect　patients＇　appearance　and　functionality.　The　preferred　method　to　address　this　issue　is　reconstructive　surgery　using　a　fibular　flap.　The　current　personalized　guide　plate　can　improve　the　accuracy　of　osteotomy　and　reconstruction,　but　there　are　still　some　problems　such　as　complex　design　process　and　time-consuming.　Therefore,　we　modified　the　conventional　template　to　serve　the　dual　purpose　of　guiding　the　mandible　and　fibula　osteotomy　and　facilitating　the　placement　of　the　pre-bent　titanium.Methods　The　surgery　was　simulated　preoperatively　using　Computer-Aided　Design　(CAD)　technology.　The　template　and　truncatable　reconstruction　model　were　produced　in　the　laboratory　using　3D　printing.　After　pre-bending　the　titanium　plate　according　to　the　contour,　the　reconstruction　model　was　truncated　and　the　screw　trajectory　was　transferred　to　form　a　modified　osteotomy　and　positioning　integrative　template　system　(MOPITS).　Next,　the　patient　underwent　a　composite　template-guided　vascularized　fibula　flap　reconstruction　of　the　mandible.　All　cases　were　reviewed　for　the　total　operative　time　and　accuracy　of　surgery.Results　The　procedures　involved　2-4　fibular　segments　in　15　patients,　averaging　3　fibular　segments　per　procedure.　The　osteotomy　error　is　1.01　+/-　1.02　mm,　while　the　reconstruction　angular　error　is　1.85　+/-　1.69(degrees).　The　preoperative　and　postoperative　data　were　compared,　and　both　p　＞　0.05.　During　the　same　operation,　implant　placement　was　performed　on　four　patients,　with　an　average　operative　time　of　487.25　+/-　60.84　min.　The　remaining　malignant　tumor　patients　had　an　average　operative　time　of　397.18　+/-　73.09　min.　The　average　postoperative　hospital　stay　was　12.95　+/-　3.29　days.Conclusions　This　study　demonstrates　the　effectiveness　of　MOPITS　in　facilitating　precise　preoperative　planning　and　intraoperative　execution　of　fibula　flap　reconstruction.　MOPITS　represents　a　promising　and　reliable　tool　for　reconstructive　surgery,　particularly　for　inexperienced　surgeons　navigating　the　challenges　of　mandible　defect　reconstruction.