The present invention provides an expansion valve control method and apparatus and an air conditioner. The degree of opening of the expansion valve when a temperature is reached and shutdown performed is preset in said air conditioner, and said expansion valve control method comprises: if, according to the obtained temperature shutdown instruction, the degree of opening of the expansion valve is adjusted down to a first open degree value and operation is performed at said first open degree value for a first duration, then adjusting the degree of opening of the expansion valve from the first open degree value to a second open degree value, said first open degree value being greater than the degree of opening when the temperature is reached and shutdown is performed, and said second open degree value being less than the degree of opening when the temperature is reached and shutdown is performed; obtaining operating data corresponding to the air conditioner operating at the second open degree value; if the operating data of the air conditioner meets a preset condition, then returning the degree of opening of the expansion valve to the degree of opening when the temperature is reached and shutdown is performed, such that the air conditioner remains in a shut-down mode. Thus the noise of the air flow of the air conditioner is ensured to be reduced or eliminated throughout the entire shutdown mode, and an impact on user experience is avoided.