The utility model discloses a horizontal well plugging simulation experiment device. The horizontal well plugging simulation experiment device is composed of a pressure-driven system, a horizontal well production simulation system and a data acquisition and analysis system. The pressure-driven system is composed of an intermediate container, a constant-flux pump, a six-way valve and a connecting pipe. The horizontal well production simulation system is composed of a simulation core barrel, a high pressure line, a controllable counterbalance valve and a calorstat. The data acquisition and analysis system is composed of a magnetostriction liquid level sensor, a magnetostriction liquid level sensor data line, a balance, a balance data line and a computer. By means of dynamic simulation of horizontal well production conditions, effluent laws of an oil-water layer in different differential pressure can be researched; and by means of simulation of capacity of plugging agent entering an oil layer section and a water layer section under the condition of bottom water or edge water or injected water, and therefore the plugging performance of the plugging agent after being glued on the oil layer section and the water layer section can be evaluated.