In order to study the influence of microporous layer (MPL) on the surface contact and transmission characteristics of titanium felt porous transport layer (PTL), the MPL was prepared by vacuum sintering after the surface of 0.25 mm, 0.4 mm and 0.6 mm titanium felts were filled with titanium powder. The surface contact area/resistance, pore size distribution and polarization curve of electrolytic water measured by laser scanning confocal microscope, mercury porosimetry and electrolysis cell, respectively. The results show that the effective contact area of the PTLs with MPL increase from 3.1% to 11.2%, 22.8% and 4.8% compared with titanium fiber felt. In addition, the contact resistances decrease to 7.07, 5.26 and 7.86 mΩ?cm2 at the contact pressure of 1.5MPa. The pore size distribution changes from the bimodal structure of PTL to the trimodal structure of PTL with MPL. The addition of a small pore size channel of 6~32 μm is conducive to liquid water transmission, meanwhile, medium & large pore size channels for gas phase transmission. The overpotential of the different thickness PTLs with MPL decrease by 12 mV、45 mV and 32 mV at 2 A/cm2 current density. The electrolysis efficiency of 0.4mm porous transport layer with microporous is the highest.