A gravel-packing sand control experimental device simulating the actual work conditions in a well consists of a thermal container, a water pump, an oil pump, a constant-temperature heating device, a screen, a beaker and a pipe. The experimental device can simulate the formation temperature and the actual production flowrate by simulating the actual work conditions in the well through the combination of formation sands in the thermal container wrapping an electric control constant-temperature heating tube, gravels in perforation holes and a water pump, an oil pump and the constant-temperature heating device. Formation water and crude oil are used, and the formation fluid has the flow characteristics of the actual spatial convergent flow, so that the actual liquid production capacity and the actual sand production rate of a production well under different water contents can be obtained. The gravel-packing sand control experimental device can determine the actual sand production rate of the formation in the well according to the sand production rate of the experimental records, thereby determining the sand-control parameters and determining the reasonable gravel size and the screen size for gravel-packing sand control in the well. Reasonable production pressure different and production allocation amount are determined for sand-controlled production wells, so that the seepage flow states of oil and water in the formation sands and gravel-packing perforation holes have better authenticity.