An excavation path planning method for excavator based on fillability is proposed. Key excavation points are calculated based on fillability, bucket parameters, and soil parameters. In the path planning of the bucket end, the arc is used to fit the transition of the path, which can reduce the vibration impact caused by sudden changes in the direction of motion. According to the excavation rules, a bucket attitude angle planning rules are developed. To maintain consistency between the attitude angle and path changes in time sequence, the bucket attitude angle is interpolated equiangular based on the bucket end path interpolation. The Hitachi Construction Machinery ZAXIS200 hydraulic excavator is automation transformed to build an excavation automation experimental platform, and several excavation experiments are conducted on flat ground with hard soil, flat ground with soft soil, and sloping mound of soil respectively. The experiments show that the excavation path planned under the method proposed in this paper can ensure a high fillability, which exceeds 130% in three environments, and the method has a small amount of computation and can be adapted to a variety of soil environments.