A composite girder analytical model under the combined action of non-uniform distributed load, axial force, bending moment and nonlinear temperature load was proposed by considering interface slip based on Euler-Bernoulli beam theory. Analytical expressions of deflection, interface shear force, slip and sectional stress were deduced. Simply supported beam and continuous beam were taken as analysis examples. The influence of interface stiffness and temperature action on interfacial slip and deflection was discussed. Results showed that deflection caused by temperature action and interface slip of composite girders were determined by equivalent temperature slip strain and equivalent temperature curvature, which could be calculated by decomposing the temperature distribution of concrete deck and steel girder into three independent parts: uniform temperature, vertical linear temperature difference and residual temperature. The interface slips of simply supported beam and 2-span continuous beam under temperature action presented an anti-symmetric distribution along the beam length, and the slip was mainly concentrated in the range of less than 2 m of the end. The tensile stress level was high at the bottom surface of the concrete deck at the end of the composite girder due to the slip, which could exceed 2 MPa, increasing the cracking risk. The deflection influence coefficient under temperature action was proposed, which could be used for quick calculation of the temperature-caused deflection of composite girders. The deflection influence coefficient is not only related to the bending stiffness ratio of composite beams with complete shear connection and no interface connection and the combined effect coefficient, but also directly affected by the temperature effect coefficient.