Self-pierce　riveting　(SPR)　with　high　connection　efficiency　and　automatic　level　is　suitable　for　joining　galvanized　steel　sheets　in　cold-formed　steel　structures.　51　SPR　joints　in　galvanized　steel　sheet　were　tested　to　study　their　shear　performance.　The　effects　of　sheet　thickness,　sheet　thickness　ratio,　and　rivet　length　on　the　failure　mechanism　and　shear　performance　were　investigated.　And　an　empirical　equation　about　the　relationship　of　sheet　thickness　and　rivet　length　was　developed.　This　paper　also　analyzed　the　applicability　for　the　existing　calculation　method　of　shear　strength　of　SPR　joints　and　the　design　methods　of　shear　strength　of　self-drilling　screw　joints　in　some　specifications,　and　then　proposed　a　new　calculation　method　of　shear　strength.　The　results　showed　that　sheet　thickness　and　thickness　ratios　were　two　critical　factors　in　the　shear　performance　and　failure　mechanism　of　SPR　joints.　There　was　an　optimal　rivet　length　for　each　sheet　thickness,　which　could　be　calculated　directly　by　the　developed　empirical　equation.　Compared　with　the　existing　methods,　the　calculation　method　of　shear　strength　for　galvanized　steel　sheet　SPR　joints　proposed　in　this　paper　considered　overall　failure　modes,　and　had　superior　calculation　accuracy　and　favorable　stability.