The invention discloses a novel high-selectivity balance filter comprising four pairs of open circuit/short circuit coupled lines, four pairs of open circuit coupled lines, two open circuit lines, seven microstrip transmission lines, and four metalized via holes. A horizontally-symmetric unbalance filter is connected though a half-wave microstrip transmission line to form a four-port balance filter. The coupling degree can be controlled effectively by adjusting parameters such as the distance and widths of the open circuit coupled lines such that a bandwidth can be controlled flexibly. By means of signal interference technology and the transmission characteristic of a loaded half-wavelength open circuit branch line, multiple transmission zero points can be generated. Thus, passband selectivity of a differential-mode signal and the inhibition degree of a common-mode signal are effectively increased. Under the effect of two transmission path signals, the balance filter achieves a good passband characteristic of the differential-mode signal and multiple zero points out of band. The inhibition frequency range of the common-mode signal achieves triple frequency multiplication. The novel high-selectivity balance filter is simple in structural design, good in electrical performance, and easy in circuit integration and system packaging.