Abstract: Using liquid polysulfide rubber as main material and manganese dioxide as curing agent, the effects of ratios of different grades of polysulfide rubbers and manganese dioxide dosage on mechanical properties of sealing putty are studied, so is the effect of treatment form of rubber bonding surface on bonding properties of sealing putty. When the amount of manganese dioxide is 12 parts, the polysulfide sealing putty has better mechanical properties. The bonding strength of putty could be greatly improved when rubber bonding surface is ground with sand belt and treated with plasma.