The embodiments of the present disclosure provide a method and an apparatus for determining an oil output quantity and a gas output quantity of a shale oil in-situ conversion, wherein the method comprises: obtaining a plurality of groups of shale samples of a target stratum of a target area; determining, according to the plurality of groups of shale samples, a first retained oil quantity, a first retained gas quantity, a Ro parameter, an oil output quantity, a gas output quantity, a second retained oil quantity, and a second retained gas quantity of each group of shale samples in the plurality of groups of shale samples under each preset temperature; building an oil output quantity model and a gas output quantity model according to the above data to determine an oil output quantity and a gas output quantity of the target area. By introducing and using parameters such as the retained oil quantity, the retained gas quantity, the oil output quantity and the gas output quantity to build accurate oil output quantity model and gas output quantity model, the present disclosure solves the technical problem in the existing methods that the predicted development potential has a large error and a low accuracy, and achieve the technical effect of accurately predicting the development potential by determining the oil output quantity and the gas output quantity of the target area.