In order to overcome the detects of Savart polarizer, which is the core device of polarizing interference system, such as complex fabrication process and high difficulty in assembling and adjusting, and to solve problems of interference fringe overlying and modulation decline caused by the assembling and processing errors of Savart polarizer, a method of a polarizing interference system based on a single parallel beam splitter (SPBS) was adopted. The structure and principle of this system were analyzed. Jones matrix and coherence intensity of the light exited from the polarizing interferometer system were derived by matrix transfer function. The interference effect is similar to that of the interferometer system based on Savart polarizer. The relationships between the optical path difference of the system and the incident angle and the incident surface were also analyzed. The correctness of the theoretical analysis was verified by experiments. The results show that because SPBS is simple in structure and not required Multiple unit combinations, there is no assembly error, and the processing error will be greatly reduced.