As a rapid dieless production method, 3D printing is promising to avoid the high cost of mold manufacturing and maintenance in the preparation of sealing glass preforms. Glass preforms are prepared by selective laser sintering (SLS) with granule and curing agent as main ingredients. The experimental results show that sealing glass powder granule can be applied to SLS process by powder laying, while polyethylene glycol (PEG) is used as binder to form granule, and polystyrene (PS) with a proper mass fraction of 20% is used as curing agent for laser sintering. Preforms with regular size can be obtained by selective laser sintering the homogeneous mixture of curing agent and granule. After laser sintering, preforms have to be heated to expel the organic agent, and then it becomes the sealing glass preforms meeting the strength requirement. The technology can be applied to the rapid dieless manufacturing of sealing glass preforms.