The invention discloses a gas well surface layer well completion liquid-solid separation construction process, which comprises steps: a circulation tank is isolated, bottom flow of a centrifugal machine is guided into a tank surface transition slot by remoulding a bottom flow pipeline of the centrifugal machine which is arranged on the circulation tank, G320 which is 0.25-0.4% in mass percent is added into the circulation tank which is filled with well completion liquid on a surface layer, the well completion liquid in the circulation tank is obviously flocculated to separate out clean water after being stirred for 10-15 minutes, the centrifugal machine is opened to adjust the rotating speed to be 1600-2000r/min, and separates solid and liquid, a sand outlet of the centrifugal machine is extremely dry solid particles, the bottom flow is clean water, rho (Rho)=1.0-1.02g/cm3, FV=27-28S, and the clean water of the bottom flow is guided into a clean water storage tank through a transition slot to separate solid and liquid of gas well surface layer well completion liquid. A solid phase in the well completion liquid is peeled from a drilling fluid system, and is subsequently processed through curing and transferring measures and the like. The rest of the liquid phase is of a clean water state, is smaller than 1.02g/cm3 in density, is smaller than 28S in funnel viscosity, thereby solving the problems that the surface layer well completion liquid can not be discharged and pollutes surrounding environment.