When a parallel beam light incident to a Dove prism, the manufacturing errors of Dove prism result in the tilted or lateral displacement at the emergence surface of the Dove prism. As a result, the coupling losses of optical signals are induced in an optical rotary joint using a Dove prism. The influence of manufacturing errors of Dove prism on coupling loss is analyzed both in theory and simulation using the method of light ray tracing. The analytical result shows that the coupling losses due to the manufacturing errors would increase as the error in base angles and the pyramidal error increase. Afterwards, according to the theoretical results and the demands of multi-channel optical rotary joint, 5 pieces Dove prisms are designed and manufactured, and then the coupling loss is measured and corrected, which further verifies the validity of the theory.