The invention discloses a harmonic oscillator of a solid fluctuation gyro, which comprises a resonance ring (1), a resonance transmission part (2), a chassis (3) and a piezoelectric element (4), wherein, the resonance ring (1) is connected with the chassis (3) through the resonance transmission part (2), the resonance transmission part (2) is composed of support beams (21) which are uniformly distributed in the circumferential direction, and the piezoelectric element (4) is arranged on the support beams (21). The invention further discloses the solid fluctuation gyro provided with the harmonic oscillator. The solid fluctuation gyro and the harmonic oscillator of the invention have the advantages of high sensitivity, good sensing effect, convenient machining, low machining cost, simple mechanical balance procedure and the like.