The invention relates to a coarse-grained soil filler gradation automatic identification method based on image matching and an application system, and the method comprises the steps: collecting coarse-grained soil filler images with various particle sizes, forming coarse-grained soil particle identification templates with various particle sizes, and constructing a template library; collecting filler images including various gradations, respectively identifying and matching each filler image with a coarse-grained soil particle template in the template library to obtain the particle size, distribution and shape category of coarse-grained soil particles in the filler image, and packaging each unit program into a program capable of running independently; collecting a filler image of a roadbedrolling construction site, and processing the filler image through a packaging program to obtain coarse-grained soil gradation in the filler image of the construction site. According to the method, efficient and accurate segmentation and recognition of a single particle are achieved by establishing the matching template, the automation degree is high, no complex image processing algorithm is needed, no human intervention is needed, no experience of operators is relied on, the environmental adaptability is high, and the precision is high.