Herein, a simple route to prepare porous microspheres with tuned pore structure and potential functionality based on epoxy functionalized block copolymers, poly hydroxypropyl methacrylate‐b‐ poly glycidyl methacrylate (PHPMA‐b‐PGMA), through a water‐in‐oil‐in‐water (W/O/W) double emulsion is reported. The effect of surfactant concentration and the composition of block copolymers are investigated. The solvent vapor swelling behavior of porous microspheres before and after cross‐linking is studied. It is interesting that after the swelling, the cross‐linked open pores are self‐healed to form closed pores, whereas the uncross‐linked ones are collapsed. It is believed that this observation will be useful in guest carrying and control release, and find its application in biomedical and pharmaceuticals.