This paper developes a set of automatic platform for testing scattering characteristics and uses this test platform for the experimental measurements on the surface scattering characteristics of stray light absorbing materials in a Thomson scattering diagnostic system. In the 1064 nm band, the noise floor of the test platform for the bidirectional reflection distribution function is better than 2×10 ^-5 sr ^-1. Furthermore, this test platform is employed to measure the surface scattering characteristics of standard white plates, stainless steel, black aluminum alloys, black paints, and other materials. The experimental results show that the Thomson scattering diagnostic system on the “Keda Torus” setup adopted Avian Black-S black paint and Metal VelvetTM black foil to absorb stray light. In the end, the measurement results are utilized to provide ABg model parameters for a variety of materials, offering necessary data for the ray tracing simulation associated with stray light.