The invention provides a quantitative evaluation method for oil-gas lateral shunting capacity under fault-sand configuration, and belongs to the technical field of oil and gas exploration. According to the method, the oil-gas lateral shunting capacity can be quantitatively evaluated, the evaluation accuracy is high, and the application range is wide. The evaluation method comprises the following steps of taking a plurality of reservoir sand layers of a certain single well as a sample sand layer, determining an oil-gas possibility condition in each sample sand layer according to geological data, and computing a fault-sand configuration oil-gas lateral shunting capacity coefficient corresponding to the sample sand layer; judging whether each sample sand layer can be used for laterally shunting oil gas or not according to the oil-gas possibility condition, and taking a minimum value corresponding to the fault-sand configuration oil-gas lateral shunting capacity coefficient in the sample sand layer capable of laterally shunting the oil gas as a critical value; and if the fault-sand configuration oil-gas lateral shunting capacity coefficient of an unknown reservoir sand layer is largerthan or equal to the critical value, indicating that the unknown reservoir sand layer can be used for laterally shunting the oil gas, otherwise indicating that the unknown reservoir sand layer cannotlaterally shunt the oil gas.