The invention discloses a coal mining device and method suitable for complex coal seam mining. The two ends of a coal mining machine body (3) are movably connected with rocker arms (4) correspondingly. The middle of the coal mining machine body (3) is provided with a coal falling and loading part (1) by extending towards one side. The rocker arms (4) at the two ends of the coal mining machine body (3) are symmetrically provided with rock drilling expansion fracturing devices (2) correspondingly. By adoption of the coal mining device and method, firstly, the working face of a complex coal seam fracture surface can be perforated through a rock drilling system to form a free face; secondly, expansion fracturing is conducted through an expansion fracturing device to lower the compressive strength of a coal seam, and therefore coal falling and loading are conducted through a roller on the coal falling and loading part; the roller is placed in the middle and is adjustable in height, and mechanized operation is achieved by replacing a blast mining technology with the coal mining method; and the rock drilling and expansion fracturing devices can achieve multi-freedom-degree movement to meet the perforation and expansion fracturing requirements of various angles, positions and postures, meanwhile, the two rock drilling and expansion fracturing devices work at the same time and are combined with efficient slicing coal falling equipment, and coal mining efficiency is greatly improved.