Facies, potential and source rocks of petroliferous basins are three factors controlling the traps petroliferous property, they are necessary for reservoirs to trap hydrocarbons. Under the condition that they all met their own critical conditions of controlling reservoirs, the larger the facies-potential-sources coupling index, the higher the petroliferous property of the trap. Based on the mechanism for hydrocarbon accurnulation controlled by facies-potential-source coupling, physical simulation experiment was conducted. Studies showed that sources controlled the material origin of hydrocarbons, facies controlled the pore space to store hydrocarbons, and potential was the driving force for hydrocarbons to accumulate in traps. Only when they combined with each other, could hydrocarbon reservoirs form in basins. Furthermore, the larger the grain size difference between cap rocks outside the trap and the reservoirs inside the trap was, the easier it was for hydrocarbons to migrate from wall rocks of fine grains and low porosity to reservoir of coarse grains with high porosity. Meanwhile, its critical condition was that the ratio of grain size of reservoir to that of wall rocks was larger than 2 times, or the outside capillary force was more than 2 times larger than that inside the traps. At the same time, high petroliferous property of source rocks was better for hydrocarbons to accumulate in the traps|with hydrocarbon saturation of outer source rock reached or more than 5% as the critical condition.