The invention relates to the technical field of separation membranes, and particularly discloses a preparation process of a self-supporting
gas separation membrane prepared from a
polymer-assisted monolithic
metal organic framework. Comprising the following specific steps: S1, uniformly mixing defective
metal organic framework particles with a
metal salt, a ligand and
triethylamine, pressing the mixture into a
wafer, and then putting the
wafer into a reaction kettle for heating reaction to obtain MOFsp1; s2, uniformly mixing a metal salt, a ligand and
triethylamine, re-pressing the mixture and the MOFsp1 prepared in the step 1 into a new
wafer, and putting the new wafer into a reaction kettle for heating reaction to obtain MOFsp2; repeating the operation to prepare the self-supporting integral
metal organic framework; s3, washing and
drying the self-supporting monoblock
metal organic framework prepared in the step 2 by using N, N-
dimethylformamide and
methanol respectively, then soaking the self-supporting monoblock
metal organic framework in a
polydimethylsiloxane solution, and
drying the self-supporting monoblock metal organic framework to prepare the self-supporting
gas separation membrane; the
gas separation membrane prepared by the invention has relatively high gas separation performance.