The invention discloses a filter-divider based on quarter-mode substrate integrated waveguide circular cavities; the filter-divider is formed by combining two quarter-mode substrate integrated waveguide circular cavities through signal input microstrip lines; the quarter-mode substrate integrated waveguide circular cavities are acquired by segmenting a substrate integrated waveguide circular cavity along any two mutually perpendicular magnetic walls, each quarter-mode substrate integrated waveguide circular cavity is provided with a signal input microstrip line and a signal output microstrip line respectively along its two right-angle side, and a field mode disturbance hole and a parasitic passband inhibition mode disturbance hole are arranged in each quarter-mode substrate integrated waveguide circular cavity; a signal input from the signal input end enters the two quarter-mode substrate integrated waveguide circular cavities, and the signal filtered and divided is output from the signal output ends of the two signal output microstrip lines. The size of the filter-divider is reduced significantly; with a filter and a divider combined, the filter-divider forms a high-integrity multifunctional passive device suitable for filtering and power dividing in a microwave and millimeter wave communication system local oscillator.