Novel catalytic combustion type solid rocket engine

The invention provides a novel catalytic combustion type solid rocket engine, and relates to the technical field of solid rocket engines. A square-tube-shaped grain is injected by clinging to the inner wall face of the combustion chamber, an annular grain is injected by clinging to the outer wall face of the built-in cylinder, the center of the built-in cylinder is an inner gas channel, an outer gas channel is arranged between the double-layer grains, and the structure of the double-layer grains increases the combustion area and improves the combustion efficiency. A granular low-specific-surface-area catalyst is adopted on the surface of the connecting piece, the surface is coated with iridium, catalytic combustion is achieved, the grain is fully combusted, convective heat exchange of the surface of the grain is enhanced, meanwhile, gas turbulence is caused when airflow passes through the connecting piece, and the grain is further fully combusted; and the platinum-rhodium wire is uniformly wound on the outer