Soybean hull pectin polysaccharide （SHPP） was prepared using the raw material of soybean hull. The effects of low molecular weight soybean hull pectin polysaccharide（SHPP-LMW） addition on the stability of soybean protein emulsion were explored. The changes of interfacial tension， particle size distribution， rheological properties and microstructure of polysaccharide emulsion by the addition of polysaccharides with different mass fractions were analyzed to investigate the effect of SHPP-LMW on the stability of soybean protein emulsion. The results showed that， the addition of SHPP-LMW had a great influence on the stability of soy protein emulsion. The emulsion with 0.5% SHPP LMW had lower interfacial tension， higher viscosity， more uniform particle size distribution， and the particle size and the parameters （D50， D4，3 and D3，2） were smaller. With the storage time extended， this emulsion changed little and showed a higher storage stability.