As the Quantum Detection Efficiency (QDE) of a spherical micro-channel plate in a photo-counting imaging detector is relative to the sensitivity of an Extreme Ultravialet(EUV)camera, this paper researches its characteristics and measurement. The secondary electron yield of the spherical MCP in EUV region is calculated based on the theoretical model describing secondary electron yield of the MCP, Then the QDE of the spherical MCP is measured by using a laser-produced plasma source, and an instrument for measuring the QDE of spherical MCP is built. The QDE of spherical MCP for different positions on a MCP surface is measured at different incident angles and wavelengths. The experimental results show that the QDE at an incident angle of 15° is five times of that at incident angle of 0°。