Due to the advantages of compact size, easy integration, fast response time, strong ability for controlling light, detecting without label, and flexibility in design, the photonic crystal (PC) micronano sensors show great application prospects in the fields of industrial production, ocean exploration, biological medicine testing, and environmental detection. As for the one-dimensional nanobeam and two-dimensional slab PC sensoring technologies, the key theories and experimental technique progresses of PC micronano sensing at home and abroad are analyzed from the aspects of structural design and sensoring performance improvement of sensors. Furthermore, with comparative analysis, the challenges and future development trend of PC micronano sensing technology in further application are discussed.