The invention discloses a LTCC miniaturized power gain equalizer based on a C-ring defect structure, which comprises a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer and a first metal layer stacked sequentially from top to bottom. Three metal layers; the first dielectric layer is symmetrically provided with two metallized through holes, and the second metal layer includes a first impedance resonator microstrip, a second impedance resonator microstrip, a first resistor, and a second resistor, wherein the first The resistor forms a series structure with the first metallized through hole and the first impedance resonator microstrip, the second resistor forms a series structure with the second metallized through hole and the second impedance resonator microstrip, and the third metal layer is symmetrically arranged The first C-ring is defectively grooved and the second C-ring is defectively grooved. The equalizer has the advantages of small size, large equalization amount and small insertion loss, and is suitable for adjusting the gain flatness of high-power sources working in the microwave frequency band.