The invention discloses a heavy gas leakage diffusion simulation and inhibition control test system. The heavy gas leakage diffusion simulation and inhibition control test system comprises an experiment wind tunnel, a heavy gas filling and recycling mechanism, an inhibition control unit and a data acquisition unit, wherein the heavy gas filling and recycling mechanism is used for injecting heavy gas into the experiment wind tunnel, and recycling low-temperature liquid; a natural environment simulation unit is arranged in the experiment wind tunnel to regulate natural environment parameters in the experiment wind tunnel; after the injected heavy gas is subjected to a water-curtain control test, a high-power foam control test and/or an obstacle test in the experiment wind tunnel through the inhibition control unit, the control effect is obtained by a monitoring point array at the downstream of the experiment wind tunnel. The heavy gas leakage diffusion simulation and inhibition control test system can be used for simulating and analyzing key factors which affect an evaporation rate as well as a leakage diffusion vapor temperature, concentration and distribution and the influence degree, under different leakage dimension shape positions, temperatures, humidity, wind speeds, radiation as well as active and passive control, of heavy gas, observing, extracting and analyzing minute links, tracing matter energy direction, performing mechanism study and establishing numerical simulation.