Silicon optical chip nondestructive performance characterization structure and method for silicon photon gyroscope

The invention provides a silicon optical chip lossless performance characterization structure for a silicon photonic gyroscope. The silicon optical chip lossless performance characterization structure comprises an optical engine chip, a coupling optical fiber, a photosensitive chip, a light source, a detector and a phase modulator, the optical engine chip comprises two gyro couplers, a redundant coupler and two optical gratings, the gyro couplers are Y-shaped couplers, and the redundant coupler is a 2 * 2 coupler and is located between the two gyro couplers; a port of one gyro coupler is respectively connected with a light source, a detector and one port of the redundant coupler, a port of the other gyro coupler is respectively connected with one port of the redundant coupler and two input ports of the phase modulator, and the other two ports of the redundant coupler are respectively connected with the two gratings; the two coupling optical fibers are respectively subjected to spatial optical coupling with th