In order to study the mechanical properties of porous cement concrete, two kinds of single-grain grades of basalt gravel and river pebbles are considered to be 9.5 to 13.2 mm, 13.2 to 16.0 mm, and the porosity is 18%, 22%, and 26%, respectively. Using CT scanning, universal testing machine and other technical means, the pore size distribution of porous cement concrete and its elastic modulus are obtained. The research shows that the water-cement ratio is too small, the cement inside the porous cement concrete can not be fully hydrated, and the uniform and continuous cementation layer can not be formed between the aggregate particles; the water-cement ratio is too large, the cement slurry is easy to flow and segregate, resulting in uneven distribution of pores and slurry. The optimum amount of cement is moderately just enough to completely wrap the surface of the coarse aggregate; the porosity is greatly affected by the type of aggregate, aggregate size and aggregate volume ratio, and the porosity is larger, porous cement. The cement slurry in the concrete is relatively reduced, the slurry coating on the aggregate surface is thinned, the bond strength is reduced, and the compressive strength is reduced. Compared with the crushed stone, the dispersion between the elastic modulus and the compressive strength of the porous cement concrete prepared by the pebble is compared. Under different stress conditions, the compressive strength of porous cement concrete is significantly different after 8h and 24h pressure.