To　study　the　load　transverse-distribution　calculation　method　for　a　widening　hollow　slab　bridge　with　rigid　splicing　joint,　full-scale　model　tests　were　carried　out　on　a　hollow-slab　bridge　with　8　cm　and　22　cm　pavement　and　a　widening　hollow　slab　bridge　with　rigid　splicing　joint.　The　experimental　and　calculation　results　from　the　existing　load　transverse-distribution　calculation　methods　that　assumed　the　shear　key　among　the　hollow　slabs　as　hinged　and　rigid　joints　were　comparatively　analyzed.　The　application　scope　of　these　existing　load　transverse-distribution　calculation　methods　with　the　above-mentioned　assumptions　was　discussed.　Then,　a　new　calculation　method　of　load　transverse-distribution　was　put　forward.　Further,　the　calculation　method　of　the　load　transverse-distribution　for　a　widening　hollow　slab　bridge　with　rigid　splicing　joint　was　presented.　The　results　indicate　that　the　existing　load　transverse-distribution　calculation　methods　that　assumed　the　shear　key　among　the　hollow　slabs　as　hinged　and　rigid　joints　are　applicable　for　hollow　slab　bridges　with　thin　and　thick　pavements,　respectively.　Both　calculation　methods　could　not　consider　the　influence　of　different　pavement　thicknesses　on　the　load　transverse-distribution.　Therefore,　a　load　transverse-distribution　calculation　method　that　considers　the　effect　of　pavement　thickness　was　proposed.　The　deviation　between　the　experimental　and　calculated　results　using　the　proposed　method　was　reduced　to　2.7%.　The　load　transverse-distribution　regularity　of　a　widening　hollow　slab　bridge　could　not　be　accurately　reflected　in　the　widening　hollow　slab　bridge　with　rigid　splicing　joint　irrespective　if　the　splicing　joint　is　considered　as　hinged　or　rigid　joint.　Therefore,　a　calculation　method　of　the　load　transverse-distribution　that　considers　the　splicing-joint　stiffness　was　proposed.　The　method　that　uses　the　stiffness　of　the　splicing　joint　without　considering　the　pavement　thickness　of　a　new　bridge　in　terms　of　the　stiffness　of　the　old　and　new　slabs　of　a　widening　hollow　slab　bridge　with　unequal-height　and　rigid　splicing　joint　is　proposed.　The　regularity　of　the　load　transverse-distribution　obtained　from　the　proposed　method　is　similar　to　that　of　the　experimental　result.　Therefore,　the　calculation　precision　of　the　load　transverse-distribution　can　be　significantly　improved　up　to　a　maximum　deviation　of　5.4%.　©　2019,　Editorial　Department　of　China　Journal　of　Highway　and　Transport.　All　right　reserved.