The hollow polymer latex particles with uniform size and good monodispersity were made by in situ polymerization with the non solvent method of encapsulation with cross linking modification, and the effect of cross linking monomer(DVB) use level in the shell on the synthesis process, morphology and opacity of the hollow polymer latex particles and its dry film was investigated by particle size analyzer, viscometer, acid value analysis, SEM, TEM and UV Vis spectrophotometer, differential scanning calorimetry. Test results show that when the cross linking monomer content(by mass) in the shell is less than 15% of the total monomer used, because the reduction of the cross linking monomer contents in the shell, the strength of the shell of the hollow polymer latex particles decreases, which causes the hollow polymer latex particles to be easily collapsed as well as a wider particle size distribution when the pore was swelling. When the content is greater than 20%, with the increase of the cross linking monomer use level in the shell, the strength of the shell increases and the particle size of polymer latex particles decreases, which makes the swelling become difficult. When the content is between 15%20%, the particle size distribution is uniform, shell strength is moderate with better swelling property, the film obtained from the dried emulsion which contained the hollow polymer latex particles show the optimal opacity performance.