A novel fibre high speed photography method has been developed for solid volume fraction measurement. This system mainly includes a small fibre-optic endoscope, a halogen light source, a high speed video recorder and a powerful computer with large memory. The endoscope which could be inserted into the reactors is used to form motion images of particles within the measurement space illuminated by the halogen lamp. The motion images of particles are recorded by the high speed video camera and will be processed by a series of digital image processing algorithms such as calibration, denoising, enhancement and binarisation. The solid volume fraction can be figured out by counting the particle number on each frame in the video. The feasibility and reliability of the measurement system have been tested in a pilot 3D spouted bed which is 200 mm in diameter and 1500 mm in height. The radial profile of the solid volume fraction in the spouted bed is determined using the analysis method mentioned above. The results indicate that the fibre high speed photography method is a promising tool for gas–solid flow research.