The invention relates to a micro FP cavity narrowband filter. The micro FP cavity narrowband filter includes a micro packaging filtering structure, internal devices are integrated into the same micropackaging body through the optical micromachining process, the internal devices include a semiconductor refrigerator, an FP cavity, a thermistor, a fiber and a collimator, some embodiments include a mirror, and the FP cavity and the thermistor are integrated on the semiconductor refrigerator. The micro packaging filtering structure is a packaging filtering structure of one-way input, one-way output or single-port bidirectional input and output. The FP cavity, the thermistor and the semiconductor refrigerator are integrated on the same micro packaging body, high efficiency optical coupling canbe realized, the packaged FP cavity is less affected by the external environment, moreover, the thermistor and the FP cavity are integrated on the semiconductor refrigerator, stable control of the FPcavity temperature is realized, and the micro FP cavity narrowband filter has combination of narrow line width, high efficiency, small size, high integration and good reliability and stability.