This paper analyses effects which influenced homogeneity of fiber gypsum blending and mat forming.The results were as follows:both of the blender and mat former used in this experiment had good performance and the quality of mixture and mat forming was satisfied.The piling height of fiber gypsum mixture in the bin had obvious influence on uniformity of the mat density represented by good linear relationship between the mat density and the piling height of the mixture.The board density had good linear relationship with MOR and MOE ,but had poor linear relationship with IB .The MOR,MOE ,and IB were getting higher with the board density increasing.