Disclosed by the present disclosure is a refrigerant leak detection method and device for an air conditioner. The method includes: acquiring current operating parameters of an air conditioner and environment information of a surrounding environment of the air conditioner; inputting the current operating parameters and the environment information into a trained neural network model to obtain an amount of remaining refrigerant outputted by the neural network model; and determining, according to the amount of the remaining refrigerant, whether there is a refrigerant leak in the air conditioner. The present disclosure improves accuracy of detecting a refrigerant leak in the air conditioner by means of an artificial neural network algorithm.