The special molecular sieve for insulation glass is used in drying gas in the isolated layer of IG, which can absorb moisture and residue organic substance in IG. However, the absorption capacity to nitrogen and oxygen is quite lower. With this function, the molecular sieve protects from fogging in the interlayer of IG, and decreases the internal and external pressure differences due to the temperature differences varying in seasons or day and night. The problem has been solved that distortion and breakage are caused by glass expansion or contraction when use other common molecular sieve desiccant. In this way, the lifetime of IG is prolonged to the maximum.