For the composite bridge deck system composed of orthotropic steel deck and ultra-high-performance concrete (UHPC) layer with 35 mm UHPC plate and 20 mm wearing layer, the UHPC layer is too thin to use conventional shear connectors. Therefore, an innovative shear connectors using the welded rebar mesh was proposed. Load-slip curve and ultimate bearing capacity were evaluated by push-out test. In the background of a Yangtze River Bridge, the optimal lay out of shear connectors was investigated by segmental model of a bridge deck. The test results showed that the brittle failure of the shear connectors occurred, and the ultimate bearing capacity of the shear connector with the 50 mm welded rebar mesh was 119kN. The slippage of the shear connector with the welded rebar mesh was less than that of the stud under the same load ratio. Furthermore, the stress at the bottom of UHPC layer should be considered in the arrangement of the shear connectors. Increased layout density of the shear connectors reduced the transversal and longitudinal tensile stress at the bottom of UHPC layer up to 36.3 %.