The invention relates to a water-soluble cement packaging material and a preparing method thereof. The water-soluble cement packaging material is prepared from, by weight, 80-120 parts of nanometer inorganic modified polyvinyl alcohol, 20-30 parts of water-soluble chitosan, 1-3 parts of plasticizer, 1-3 parts of surfactant, 0.2-0.5 part of defoaming agent, 0.5-0.6 part of propylene glycol fatty acid ester, 0.2-0.3 part of binder, 0.2-0.3 part of dispersant and 0-0.3 part of colorant through processing. The mass ratio of nanometer inorganic modified polyvinyl alcohol to water-soluble chitosan is 4:1, the plasticizer is a mixture of polyethylene glycol and acetamide in equal proportion, and the surfactant is a mixture of polyoxyethylene oil-based ether and polyoxyethylene octyl phenylate in equal proportion. The water-soluble material is wide in solution temperature range, high in solution efficiency and good in solution effect, debris residue hardly exists, further manual or mechanical treatment is not needed, and in addition the barrier performance and uniformity of a film are excellent.