The objective is to describe the interference degree between motor vehicles and bicycles at signalized intersection. The interference degree was expressed by conflict delay. Via analyzing the microscopic actions of the motor vehicles crossing through the bicycle flow at a typical two-phase signalized intersection, a conflict delay model of the right-turn vehicle was proposed applying the gap acceptance theory and traffic wave theory. The model was verified and compared with the existing conflict delay models. The result showed that the proposed model is stable and suitable for the condition of unsaturated to calculate the conflict delay of right-turn vehicle. Sensitivity of the conflict delay model with respect to the flow rate of the bicycle and the width of the bicycle lane was analyzed. It showed that the increase of the width of the bicycle lane within limits could reduce right-turning vehicle’s conflict delay effectively when the motor vehicle’s flow rate was higher and the bicycle flow rate was varying in a certain range.