This　study　focuses　on　the　Cu-Sn-Cu　sandwich　structure　soldering,　0.06　MPa　constant　pressure.　Different　soldering　temperatures　and　soldering　times　were　selected　based　on　the　Cu-Sn　binary　phase　diagram.　After　soldering　according　to　different　phase　composition　the　solder　joints　can　be　divided　into　three　types　of　residual　Sn/Cu3Sn-Cu6Sn5-Cu3Sn/Cu-Cu3Sn-Cu.　The　relationship　among　shear　strength　of　solder　joints　and　three　different　phases　compositions　were　researched　by　shear　experiment　of　1　mm/min　loading　rate　and　fracture　morphology　analysis.　The　results　show　that　the　shear　strength　of　solder　joints　increases　with　the　depletion　of　Sn　and　Cu6Sn5　in　sequence.　The　shear　strength　of　residual　Sn　solder　joints,　Cu3Sn-Cu6Sn5-Cu3Sn　solder　joints　and　Cu-Cu3Sn-Cu　solder　joints　are　23.26,　33.59,　51.83　MPa,　respectively.　Based　on　the　fracture　morphology　analysis,　residual　Sn　solder　joint　fracture　can　distinguish　the　morphology　of　Sn/Cu6Sn5/Cu3Sn,　indicating　that　the　crack　path　through　the　Cu6Sn5　and　Cu3Sn　phases.　In　Cu3Sn-Cu6Sn5-Cu3Sn　solder　joint　fracture,　Cu6Sn5/Cu3Sn　morphology　was　distinguished,　crack　path　through　the　Cu3Sn　phase.　When　only　Cu3Sn　phase　was　at　solder　joints,　was　Cu3Sn　only　Cu3Sn　can　be　seen　in　fracture　morphology　of　the　soldering　joints.　©　2019,　Editorial　Board　of　Transactions　of　the　China　Welding　Institution,　Magazine　Agency　Welding.　All　right　reserved.