Abstract: Ultra-high-performance concrete (UHPC) has a great potential application in composite bridges. Considering the complex interface shear between the upper chord of the steel truss and the UHPC waffle plate in the new steel-UHPC light composite truss beam, two sets of 12 stud specimens are designed for static push out tests. The experimental parameters include: stud number, stud layout spacing, reinforcement ratio, UHPC pouring method, horizontal constraint and loading mode. By increasing the transverse span of the push-out test specimens and by adding the horizontal self-restraint screw, the combined compression-bending-shear stress state in the actual joint can be well simulated. The test results show that: the failure mode of a stud connection at the steel-UHPC interface is that the whole stud group is cut along the upper edge of the root weld, and the UHPC part shows no obvious failure phenomenon. Compared with the traditional pure shear push-out test, the shear capacity can be increased by about 12%~41% and the interface slip can be greatly reduced under the coupled compression-bending-shear action. Finally, one calculation formula of stud capacity considering the coupling effect of interfacial compression-bending-shear is proposed.