There are some problems of easy damage and arduous maintenance in the expansion joints at abutment, and a new type of single expansion joint bridge (SEJB) is herein proposed to deal with them. To investigate the mechanical characteristics of SEJB under temperature load, simplified calculation model is proposed in this paper. Considering the distribution and development rule of cracks in approach pavement, theoretical formulas for internal force and deformation were derived, and calculation programs were compiled. For example, under the effect of temperature drop of 20 ℃, the maximum steel stress was 148 MPa, and the maximum crack width was 0.185 mm for a 280 m length SEJB, which met the requirement of criterion; the additional stress of beam was 0.105 MPa, which could be ignored. Moreover, taking the different temperatures into account, parameter analysis was performed. The results show that the 30 m length pavement can well meet the needs for use. Internal force is reduced by using bearing and cushion materials with low surface friction coefficient, and a biaxial geogrids is recommended.