The invention provides a test method of cement based material fluid permeability, and relates to the test method of the fluid permeability of porous materials such as cement based materials. The testmethod aims at solving the problems that the operation of the existing fluid permeability test is complicated; the problem of test failure due to poor sealing performance often occurs. The test methodcomprises the following steps of 1, installing a sealing sleeve on the upper plate surface of a bottom plate; installing a sleeve outside the sealing sleeve; covering a top cover on an upper tube opening of the sleeve; forming a pressure chamber between the sealing sleeve and the sleeve; 2, installing a base and a test piece in a shrinkage sleeve pipe; sleeving the shrinkage sleeve pipe into thesealing sleeve; inserting a plunger piston into the shrinkage sleeve pipe; 3, injecting water into a water injection passage in the bottom plate so that the lower part of the test piece is fully filled with water; 4, filling the pressure chamber with water; exerting constant water pressure at the bottom of the test piece; measuring the volume of the moisture permeate into the test piece; calculating the moisture permeability. The invention provides a fluid medium permeability test method; the side surface sealing effect of the test piece is strictly ensured; meanwhile, the advantages of simpleand convenient operation and time and labor saving are realized.